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Aalto University, School of Electrical Engineering
Automation and Electrical Engineering (AEE) Master's Programme
ELEC-E8002 & ELEC-E8003 Project work course
Year 2017
Final Report
Project #23
ExperimentControl for TRES
Date: 29.5.2017
Henri Varjotie
Borys Plyenkov
Kang Jiao
Qianqian Qin
Yi Zhang
Esko Honkala
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Information page Students
Henri Varjotie
Borys Plyenkov
Kang Jiao
Qianqian Qin
Yi Zhang
Esko Honkala
Project manager
Henri Varjotie
Official Instructor
Noora Isoaho
Other advisors
Starting date
5.1.2017
Completion date
29.5.2017
Approval
The Instructor has accepted the final version of this document
Date: 26.5.2017
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Abstract The project name ExperimentControl for TRES (Temporal resolution of electrochemical sensors)
comes from the fact that the system is a test setup for assessing the temporal resolution of
electrochemical sensors. Temporal resolution defines the accuracy of the sensors with respect to
time.
In this project, a three-electrode setup was used for assessing the temporal resolution. First, the
electrodes were placed in self-designed sensor housing. Next, two solutions were run through the
sensor housing, one at a time. Changes in the current response and the rise time between the current
plateaus give information about the temporal resolution. The current response is measured with a
third party potentiostat which is also controlling the potential in the electrochemical cell. The
objective of this project was to develop a system which enables user to easily measure the temporal
resolution.
The outcome of this project is a system consisting of hardware and software. Software is the brains
of the system and it controls the hardware based on parameters the user sets in the user-interface.
Software also controls the potentiostat, which is doing the actual measurement, and obtains the
measurement data from it. From the data, the software plots a current versus time graph in the user-
interface. The software also enables user to download the data as a CSV-file (comma separated
value). From the measurement data, the user can calculate the temporal resolution of the
electrodes/sensors.
The system reached its objectives by being easy-to-use and providing quite noise-free measurement
data. The system has automated and manual modes which gives the user possibility to do more
variable test runs. The system is also quite simple which makes it modifiable.
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Table of Contents Abstract ................................................................................................................................................ 3
Table of Contents ................................................................................................................................. 4 1. Introduction .................................................................................................................................. 5 2. Objective ...................................................................................................................................... 7 3. Project plan .................................................................................................................................. 8
3.1. System design ........................................................................................................................ 8 3.2. Quality ................................................................................................................................... 8 3.3. Schedule ................................................................................................................................ 9 3.4. Cost plan .............................................................................................................................. 10
4. Design ........................................................................................................................................ 11
4.1. Components ......................................................................................................................... 11 4.1.1. Housing Platform ......................................................................................................... 11 4.1.2. Electrical components .................................................................................................. 12
4.2. System design and functionality.......................................................................................... 13 4.2.1. Overall design .............................................................................................................. 13 4.2.2. Hardware ...................................................................................................................... 14 4.2.3. User-interface ............................................................................................................... 16
5. Test results and analysis ............................................................................................................. 19 5.1. Final test measurements and results .................................................................................... 19 5.2. Conclusions ......................................................................................................................... 24 5.3. System improvements ......................................................................................................... 25
6. Reflection of the Project ............................................................................................................ 27 6.1. Reaching objective .............................................................................................................. 27
6.2. Timetable ............................................................................................................................. 27 6.3. Risk analysis ........................................................................................................................ 29 6.4. Project Meetings .................................................................................................................. 31
6.5. Quality management............................................................................................................ 32
6.6. System design ...................................................................................................................... 33 6.7. Cost plan .............................................................................................................................. 33
7. Discussion and Conclusions ...................................................................................................... 35
List of Appendixes ............................................................................................................................. 37 References .......................................................................................................................................... 37
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1. Introduction Glutamate is the most common neurotransmitter in the human body. Balanced glutamate
homeostasis is important for human beings and all mammals. Problems in glutamate regulation
system are strongly linked to neurological diseases, such as Alzheimer's disease, schizophrenia,
Parkinson's disease, amyotrophic lateral sclerosis and Huntington disease. [1] The purpose of this
project work is to build equipment for assessing the temporal resolution of glutamate sensors.
Glutamate is not electrochemically active, which makes its detection more difficult because direct
electrochemical measuring methods cannot be used. However, a certain enzyme can catalyze a
reaction with glutamate where hydrogen peroxide is produced as the end product. Hydrogen
peroxide is electrochemically active allowing the use of electrochemical methods. The amount of
hydrogen peroxide depends on the initial amount of glutamate. Measuring the amount of hydrogen
peroxide instead of the direct measuring of glutamate makes this measuring method indirect. Hence,
by using this indirect measurement method, the amount of glutamate can be determined. [2]
Electrochemistry is a part of the physical chemistry that studies the oxidation-reduction phenomena.
Those reactions generate or consume electrical energy. When the electrode made of conductive
material is placed in the electrolyte solution, a potential difference is formed between the electrode
and the electrolyte solution. This potential is impossible to measure directly, so another electrode is
needed to measure the difference between the two-pole potential of the two electrodes. For the
different materials, a standard potential is obtained by comparing the electrode's potential with the
potential of the hydrogen electrode. Potential of the hydrogen also divides metals into noble metals
and non-noble metals in the electrochemical voltage series. [3] Oxidation reactions occur on the
surface of the other electrode which arises current that is utilized in this project.
This work is based on amperometry which is one of the electrochemical methods. Amperometry is
technique where voltage between working electrode and reference electrode is maintained. The
current arises from electrochemical reactions occurring on the working electrode surface.
Amperometry provides information about current versus time. [4] In this project work a three-
electrode system is utilized. It consists of a working electrode, a reference electrode and a counter
electrode. Amperometry can be used to obtain some information about the change of current versus
change of potential properties of detected substance. For example, potential levels can be changed
step by step and observe the changes in current response. Significant benefit of amperometry is its
speed. The only limiting factor is hardware which is used during measurements.
A device called potentiostat is used for the amperometric method to measure the current between
electrodes. The potentiostat is an electric hardware to control various amount of electrode cells and
run most electroanalytical measurements. The main principle of the potentiostat is based on the
correlation of the potential from electrochemical reaction and current. The main component of the
potentiostat is an operational amplifier with negative feedback. The negative feedback guarantees
the better stability and increased noise tolerance. The solution and electrodes form the system where
that external potentiostat is needed to analyze the measurements. The potentiostat is needed in the
project because it measures current over time which can be analyzed using a computer. From the
current versus time plot, temporal resolution assessment can be made. [12]
The main task of our project is to implement a system, which makes it possible to assess temporal
resolution of an electrochemical sensor. Expensive sensors are useless, if there are no reliable
methods to assess their accuracy and performance. The temporal resolution defines the precision of
the sensors with respect to time.
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Some neurochemical reactions can happen very fast. That is why it is important to be able to
perform measurements within short time periods reliably. For example, some glutamate transient
values are milliseconds class [5]. Our system will present the results in user-friendly environment.
The data from the potentiostat will be shown clearly and it can be easily analyzed.
The end product of our project is called ExperimentControl for TRES. TRES means the temporal
resolution of electrochemical sensors which our product is measuring. ExperimentControl contains
the device for controlling the experiment and a computer software with an easy-to-use user-
interface. The name ExperimentControl comes of course the fact that the system is controlling an
experiment where temporal resolution of electrochemical sensors is measured. The device of this
project will be given to Microsystem technology group in Aalto University.
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2. Objective The main objective of this project was to build a system for assessing the temporal resolution of
electrochemical sensors. The system consists of liquid tanks, sensor housing for three electrodes,
pump, valves, microcontroller and PC software. The system was required to be connected to third
party potentiostat device which would collect data from sensors. The collected data would then be
sent to PC software from which the data can be downloaded and displayed in a more user-friendly
manner.
The system was required to support at least two different liquids and to change fast between these
liquids. The system was also required to be easy to use and to have a proper user manual with
troubleshooting guidelines.
Similar project was done last year. However, their measurement results had a lot of noise in them.
Therefore, the main objective of this project was to filter away all the possible noise in the
measurement results by enhancing the system.
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3. Project plan In this section, success and changes are compared with the project plan are presented. The Project
plan is added as Appendix 1.
3.1. System design The planned system design consisted of pump, microcontroller, sensor housing for attaching three
electrodes, potentiostat (variable power source and current meter in the Figure 1), tubes for liquids,
waste tank and electrically controlled valves for various amount of liquids. The basic block diagram
of the planned system is represented in Figure 1.
Figure 1. Figure representing the planned system design.
3.2. Quality The quality in the project plan consisted 5 aspects: Whether the test bed can work successfully, how
well does the test bed work, how easy it is to use, how well is the noise handled and can the group
give a satisfactory analysis based on the data obtained.
The first aspect of quality evaluates how well the test bed works as planned and does it have all the
necessary functionalities.
The second aspect is to evaluate how well the test bad provides the measurement data and is it
sufficient. One evaluation criteria of it is also does the test bed support more than two different
liquids.
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The third aspect of quality addresses the user-friendliness of the system. It evaluates is the user-
interface clear and intuitive to use and how easy it is to setup the whole system.
The fourth aspect of quality is related to the quality of the measurement data. This has been defined
as a separate quality criteria since reducing the noise to minimum was our main goal in this project.
The standard deviation of the measurement data should be calculated to see whether the noise is
reduced enough.
The fifth and the final quality aspect is related to the analysis of our measurement data. The main
goal of the analysis is to discover how the temporal resolution can be calculated from the data
obtained from the measurements.
3.3. Schedule The planned schedule was based on milestones. These milestones consisted of important dates set
by course staff and our own calculations of when certain parts of the project should be ready. Table
1 represents these milestones.
Table 1. Table representing the planned milestones of the project.
Milestone Description Deadline
M1 Submit the Project plan 26.1.
M2 Ordering of the hardware parts 24.2.
M3 Submit Presentation Slides for Business aspects seminar 2.3.
M4 Submit the Business aspects document 10.3.
M5 Hardware design 1.4.
M6 Software design 6.4.
M7 Integrating the hardware and the software design 13.4.
M8 Testing the system 20.4.
M9 Analyzing the results 1.5.
M10 Submit poster designs for Final gala 9.5.
M11 The Final Gala takes place 16.5.
M12 Submit final reports 29.5.
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3.4. Cost plan The cost plan of the project was implemented strongly based on what the budget for this project was
last year. The planned costs are represented in Table 2.
Table 2. Table representing the planned costs of the project.
Item Price (EUR) Remark
Liquid tank 10-20 3 for input liquid and 1 for waste
Valve 50-100 -
Pump 50-100 Price varies according to the type
Microcontroller 50 -
Sensor housing 30 Possibly can be waived by 3D printing
service in university
Others 130-150 For expenses to be determined later
Total 320-450 Approximately 400 EUR estimated
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4. Design This chapter describes the overall design and functionality of the ExperimentControl system.
4.1. Components This subchapter lists the main components of the ExperimentControl hardware.
4.1.1. Housing Platform
The new Housing Platform was printed by 3D printer with 8 mm input and 3.8 mm output hole
which is designed to increase the measuring time of the sensor (Figure 3). The tubes connect to the
input hole with a connector. While, at the top of the housing platform (Figure 4), there are two slots
and a small round hole; The two slots are used by two electrodes (working and counter electrodes)
that are placed face-to-face and the round hole is used for the reference electrode. The sensor
housing (Figure 2) from last year is composed with two parts which is not so easy to assemble and
which makes the sensor housing less stable. After experiments with this housing platform, we
discovered that the sensors are not fully inside the liquid, which might cause some noise to the
current. For this reason, we implemented a new one which is integrated into one so that the
electrodes can be stable in the platform. The new housing also has cone-like inside which reduces
the output of liquid and increases the input of the liquid. This results that the sensors will be all the
time inside liquids and no air cannot get between the electrodes.
Figure 2. Figure showing the sensor housing from last year. [11]
Figure 3. Figure showing the sensor housing model in Autodesk 360 software.
Figure 4. Figure showing the sensor housing model in Autodesk 360 software.
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Figure 5. Figure showing the 3D-printed sensor housing.
4.1.2. Electrical components
Arduino Uno R3 USB Microcontroller
The Arduino Uno is selected as the Microcontroller for ExperimentControl system because there
are 14 digital I/O ports and 6 analog inputs which is sufficient for this system. The board is also
compact and small. It has a USB connection which could be used by the UI to communicate with
MCU. The Arduino Uno is shown in Figure 6.
Figure 6. Manufacturer's picture showing the Arduino Uno R3. [4]
Arduino Compatible Mega Motor Shield
The Arduino Compatible Mega Motor Shield is used as an extension to Arduino board to make it
easier to control the pump. The Mega Motor Shield works in 5-28V voltage range and it supports
up to 30A of current. It is designed as a H-bridge which means that the circuit in it enables to
provide voltage to the load (for example a dc motor) in either direction. Due to this, for example the
dc motor can be rotated in both directions. [5] The Mega Motor Shield is shown in the Figure 7.
Figure 7. Seller's picture showing the Arduino Compatible Mega Motor Shield. [5]
114-OEM Pump
The reason that we choose 114-OEM pump (Figure 8) is that it is controlled by DC drive (24VDC)
and it delivers the liquid flow up to 340 ml/min which is sufficient for our system. Compared to the
pump bought last year, the structure of 114-OEM pump is more stable and powerful which can be
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used for tubes with thick wall. This pump is also very small and compact. Other benefit of the pump
is that its head has no contact with the liquid directly. This enables user to just change the tubes and
no addition cleaning for the pump is required. [8]
Figure 8. Seller's picture showing the 114-OEM Pump. [6]
S305 Pinch Solenoid Valve
As is shown in Figure 9, Pinch Solenoid Valve is a two-channel valve with mutually exclusive
logic, which means one tubing is normally open while the other one is normally closed. The
nominal voltage of the solenoid is 24V, it has better shut-off ability than 12V solenoid after our
experiments with different solenoid valves. [9]
Figure 9. Seller’s picture showing the S305 Pinch Solenoid Valve. [7]
4.2. System design and functionality This subchapter describes the overall design and functionality of the ExperimentControl system.
4.2.1. Overall design
The overall system design consists of 5 parts: User-interface, background software behind the user-
interface, software inside a microcontroller, electrical hardware and parts in which liquids are
moving in. The software code is made using C++ and the microcontroller code is made using
Arduino based C which is a mixture of C language and C++ libraries. The user-interface software is
used for controlling all the parts of the system. The software is downloaded to computer with
installer (see Appendix 3: User manual for reference). The next chapters describe more in detail
how the parts of the system work both individually and together. Figure 10 shows the whole system
during testing.
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Figure 10. Figure showing the whole system during testing.
4.2.2. Hardware
The system hardware consists of microcontroller (Arduino), motor control shield, relay module,
pump, solenoid valve and power source. The power source has 24V output and all the parts except
microcontroller and relay are using that directly as their input voltage. The motor control shield will
convert the 24V input to 5V for the microcontroller. Figure 11 presents the basic block diagram for
the whole system hardware.
Figure 11. Hardware block diagram representing the actual system having only two liquid tanks and one solenoid valve. Supports only two types of liquids.
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Other parts of the hardware are sensor housing, liquid tanks, waste tank and tubes. Sensor housing
is 3D-printed plastic system that enables the user to insert sensors inside a tube in which the liquids
used for measurement are flowing through. The material of sensor housing is PLA which is a strong
plastic material but can be easily molded with low temperatures and therefore 3D-printed. The
liquid tanks are basic plastic liquid holders which can be attached to tripod holder. The tubes are
made of pumpsil (platinum cured silicone tubing) and their inner diameter is 1.6 millimeters. The
waste tank can be anything, for example a glass bowl. The materials of the housing, tubes and waste
tank should be of course suitable for the liquids in use. In our project, the concentration of the
hydrogen peroxide solution was only 1 mmol/l and therefore the PLA housing for example, was
able to stand it.
The system hardware receives its control signals from the computer software user-interface which is
presented in the next sub chapter. The microcontroller takes one byte sized commands through USB
serial communication line. Based on the commands, either the pump is started or the solenoid valve
is positioned in way that only one liquid can go through. The microcontroller has C-based code
inside which is used for receiving the commands and acting accordingly based on those commands.
The microcontroller is communicating with the pump through the motor control shield. It is using
pulse-width modulation to send correct signal values to the motor control shield which then
converts them to correct voltage signals. The voltage signals are then used for rotating the pump.
The pump itself has a dc-motor in it which takes certain voltage signals to its pins and rotates
according to those voltage signals.
The solenoid valve is controlled by using a relay. The relay is connected to the microcontroller
which either sets it to on or off position. Based on the position of the relay the current from the
power source will either flow to the solenoid or not. If the current flows to the solenoid, it will
suppress the tube from other liquid and when the current does not flow to the solenoid, then the
solenoid will suppress the tube of the other liquid. By controlling the position of the solenoid valve,
the wanted liquid is moved to the pump. The pump then pushes the liquid through the sensor
housing to the waste tank.
In the sensor housing, there are positions for three electrodes: working, counter and reference
electrode. From the current that is caused by electrochemical reactions on working electrode
surface, a potentiostat described in the previous chapters is producing measurement data (current
versus time) and that data is then transferred to the user-interface of the software.
The electrical components of the hardware (solenoid, pump, microcontroller, relay and motor
control shield) are placed in a plastic box which will cover the system from liquid spills. Figure 12
presents the positioning of the electrical components in the mentioned box.
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Figure 12. Hardware box containing electrical parts of the system.
4.2.3. User-interface
The user interface (UI) was developed using Qt 5.8 application framework. The UI layout was
designed by dragging and placing widgets in Qt Creator. Qt uses standard C++ with extensions, for
example signals and slots, which makes event handling more simple. This helps in the development
of UI which receives a set of event information and then it should process the information
accordingly.
The connection between UI and other software parts is realized based on the signals and slots
mechanism. A C++ object called ArduinoSerial is created based on the serial class for serial
communication. This communication is done through the USB-connector readily available on
Arduino. When pressing a button, a signal is emitted, and its corresponding slot function associated
with the object ArduinoSerial is called. The code to control the potentiostat is executed in the
background thread when users start the experiment via UI buttons and it utilizes Component Object
Model COM interface provided by Gamry Electrochemical toolkit for control of potentiostat and
data acquisition. Figure 13 and Figure 14 shows the appearance of the UI.
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Figure 13. Figure showing the main window of the UI.
Figure 14. Figure showing the dialog window of the UI.
As the Figure 13 shows, in the main window, there are several main parts: COM port
(Communication port) selection box, Mode selection box, Automatic Controls box, Manual
Controls box, Data graph viewer and Data From potentiostat Table. The Data graph viewer real-
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time presents output data plot in time sequence, and the Data From potentiostat Table shows more
detailed information of obtained data.
As the Figure 14 shows, there is a dialog window related to setup menu. In this window, two basic
settings of Gamry can be set. More information about the program and how to use it can be found in
the Appendix 3: User manual.
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5. Test results and analysis This chapter presents the results from testing the ExperimentControl system and analysis of those
results.
5.1. Final test measurements and results This subchapter represents the results from final system testing and analysis of those results.
Measurements were made in the Micronova lab. Total of 8 measurements were made. All the
measurements have the same setup values which are
Voltage: 0.5 V
Time: 170 seconds
Interval: 25 seconds
Delay: 5 seconds.
The setup was not changed in anyway during these test runs. Only difference is that new hydrogen
peroxide solution was made and mixed with the first solution in measurement 5. The hydrogen
peroxide was done same way in both solutions. We mixed in 100ml bottle 10.5 μl of 30% hydrogen
peroxide and PBS (basically salt liquid with pH ≈ 7). Therefore, the concentration of the hydrogen
peroxide solution should have been around 1 mmol/l. Slight changes in the concentrations of these
solutions might have occurred and caused changes to the values of the current peaks.
From the measurement data, diagrams were drawn. Figure 15 represents one of those diagrams. All
the diagrams can be seen with better quality in Appendix 2: Final test results.
Figure 15. Figure showing a graph plotted from the data of measurement 7.
From the results, Standard Deviation of the noise could be calculated and the results are presented
in Table 3 on the next page.
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Table 3. Table representing the Standard Deviation and Relative Standard Deviation of the
measurements.
M SD1 RSD1 SD2 RSD2 SD3 RSD3 SD(mean) RSD(mean)
1 1.1676*10-7 1.12% 7.8720*10-8 0.77% 8.4004*10-8 0.86% 9.3161*10-8 0.92%
2 6.4517*10-8 0.56% 7.1207*10-8 0.65% 4.2465*10-8 0.39% 5.9397*10-8 0.53%
3 5.8707*10-8 0.56% 5.5790*10-8 0.54% 3.5629*10-8 0.35% 5.0042*10-8 0.48%
4 5.8778*10-8 0.50% 8.6191*10-8 0.76% 7.4808*10-8 0.66% 7.3259*10-8 0.64%
5 7.9947*10-8 0.67% 9.7037*10-8 0.82% 4.3209*10-8 0.37% 7.3398*10-8 0.62%
6 6.1593*10-8 0.45% 5.7288*10-8 0.42% 4.3545*10-8 0.34% 5.4142*10-8 0.40%
7 6.9659*10-8 0.50% 6.3811*10-8 0.48% 6.0633*10-8 0.46% 6.4701*10-8 0.48%
8 1.3949*10-7 1.11% 6.8936*10-8 0.55% 8.2212*10-8 0.65% 9.6881*10-8 0.77%
The data of the table is calculated like this: The three sets of current values in the time periods 40s-
50s, 90s-100s and 140s-150s are extracted. These time periods were decided by visual inspection of
the graphs and estimating steady current from the current values. Then the standard deviation of
these sets of data, denoted as SD1, SD2, SD3 respectively, are calculated by the MATLAB built-in
function. The RSD is calculated by dividing the corresponding SD by the mean of the current
values.
The results show the noise is satisfactorily handled. The very small values of SD indicate that the
variation of current is relatively small. The RSD describes the spread of data with respect to the
mean value. Here almost all the RSD results are smaller than 1.00%, meaning that the data points
are tightly clustered around the average.
The first set of results seem relatively less steady (larger RSDs). This is due to that there might be
some air in the tubes when starting the testing first time. Therefore, before actually taking the
measurements, the pump should be run a while with one solution to remove all the air from the
tubes and the sensor housing.
The fifth set of results also seem relatively less steady (larger RSDs) in the first two time periods,
because the two different H2O2 solutions are mixed before doing experiment. The H2O2 fluctuation
leads to current variation.
The eighth set of results also has large RSD value in the first time period. The reason for this higher
variation in current is unknown. The most probable reason for this is that there was a difference in
hydrogen peroxide concentration and that caused the higher current. Therefore, it is important to
mix the solutions properly and also be sure not to mix two different hydrogen peroxide solutions
together in the tube holders of the system.
Based on the data gained from the measurements, also the rise and fall time calculations were made.
The rise time is the time it takes when the current increases from 0.1 ∗ 𝐼(𝑚𝑎𝑥_𝑚𝑒𝑎𝑛). . .0.9 ∗𝐼(𝑚𝑎𝑥_𝑚𝑒𝑎𝑛). The fall time is the time it takes when the current decreases from 0.9 ∗𝐼(𝑚𝑎𝑥_𝑚𝑒𝑎𝑛). . . .0.1 ∗ 𝐼(𝑚𝑎𝑥_𝑚𝑒𝑎𝑛) respectively. All these statistical values have been
calculated by using self-implemented MATLAB script. Table 4 represents the rise and fall time
calculations.
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Table 4. Table representing the rise and fall time (s) calculations of the measurements.
M Rise
time 1
(s)
Rise
time 2
(s)
Rise
time 3
(s)
Fall
time 1
(s)
Fall
time 2
(s)
Fall
time 3
(s)
Mean Rise time
± STD (s)
Mean Fall time
± STD (s)
1 2.940 3.920 4.010 4.500 4.290 4.710 3.623±0.5935 4.500±0.2100
2 3.780 4.450 4.350 4.880 4.800 4.370 4.193±0.3614 4.683±0.2743
3 3.750 4.680 4.360 4.630 4.670 4.640 4.263±0.4725 4.646±0.0208
4 5.700 4.120 4.350 4.530 4.200 4.060 4.723±0.8536 4.263±0.2413
5 4.520 5.220 3.840 4.170 4.610 4.120 4.526±0.6900 4.300±0.2696
6 3.670 4.120 5.320 4.040 4.160 4.770 4.370±0.8529 4.323±0.2696
7 3.330 4.500 4.190 3.910 4.260 4.460 4.006±0.6062 4.210±0.2784
8 3.670 4.460 4.680 4.190 4.140 4.550 4.270±0.5311 4.293±0.2237
Table 4 presents all rise and fall times of each measurement. In addition, their averages are also
presented respect to each measurement. Moreover, standard deviations for rise and fall times are
presented as well. Because of the noise, the maximum current values are calculated as an average of
the area where the current is nearly constant over time. Figure 16 and Figure 17 show the averages
for each measurement separately.
Figure 16. Figure representing averages of the rise times for each measurement. Red bars on the figure represents STD values as errors for the rise times.
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Figure 17. Figure representing averages of the fall times for each measurement. Red bars on the figure represents STD values as errors for the fall times.
As can be seen from the above figures the average rise times are around 4.2 seconds and the
average fall times are around 4.4 seconds. The STDs for rise times are much higher than the STDs
for the fall times. Also, the fall times vary less than the rise times.
The reasons for fluctuations in rise and fall times might be caused by that the H2O2 solution is not
properly mixed in the tubes. There might be left some PBS in the tubes and that would change the
concentration of the flowing H2O2 solution. Changes in the concentration might change the reaction
times on the surface of the working electrode and also change the amount of maximum current.
Other reason for different rise and fall times could be that the surface of the working electrode is
slowly occupied during the measurements. When H2O2 reacts with platinum, the H2O2 breaks into
OH molecules which will occupy the surface of the platinum. The OH molecules then react with H+
ions and this will produce H2O molecules that will occupy again the surface of the platinum. [10]
Due to these reactions, the working electrode surface is occupied and this might affect the rise and
fall times as well as the current.
Based on the calculations of the rise and fall times, we produced graphs of representing the
distribution of the rise times (Figure 18) and fall times (Figure 19).
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Figure 18. Figure representing the distribution of rise times.
Figure 19. Figure representing the distribution of fall times.
From the Figure 18, we can see that the rise times are approximately normally distributed which
would indicate that our system can produce similar results between measurements. However, the
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Figure 19, which shows the distribution of the fall times, does not follow any known distribution.
On the other hand, the variation of the fall times is much less than the variation of rise times.
Therefore, we could say that our system is producing quite similar results. Of course, defining the
real normal distribution of our system would need a lot more measurements and a lot more data.
Due to time restrictions, that large amount of data would not have been possible to produce. Also,
defining properly the reliability of our system, would require much more data.
5.2. Conclusions This subchapter summarizes the conclusions made from the results in the previous subchapter. It
also lists measures that can be done to reduce noise.
As was mentioned before, similar project was done last year and we continued their work. The basic
functionality of our system has come from their system. However, their results (Figure 20)
contained too much noise. Therefore, reducing the noise was our main goal in this project.
Figure 20. Figure representing last year's group final results. [11]
Based on the data represented Table 3, the standard deviation of our measurements is quite small.
This indicates that the amount of noise has reduced a lot, especially if compared to the results of the
previous group (Figure 20). The main reason for the improvement is probably because we replaced
the pump with much more professional one and we designed new sensor housing. The noise in both
last year and this year systems is most probably caused by vibrations in the liquid flow caused by
the pump and air bubbles in the tubes and in the sensor housing. Also, it is important that the
electrodes are fully covered with liquid or otherwise the current between them cannot be static or it
does not flow between them at all. By making the way for the liquids in the sensor housing as small
as possible, the more sufficient is the amount of liquid covering the electrodes. What also improved
the sufficiency of the liquid is that we designed our sensor housing in a way that the input hole for
the liquid is larger than the output hole which ensures that the sensor housing is all the time full of
liquid and any air cannot go there.
Other reasons for noise and current variation might occur due to variations in concentration of
H2O2. This could be avoided better with properly mixing the H2O2 solution and changing the system
design. The system design change would require two pumps and two solenoid valves. The both
liquids would then have their own paths to the sensor housing and therefore there might not be so
much variation of concentration.
Page 25 of 37
Based on the data calculated in the above subchapter (5.1 Final test measurements and results) the
rise times followed narrow normal distribution and the fall times were quite close to each other with
only a little error. This would indicate that our system is producing quite similar results from
measurements. However, as stated already before, the amount of data is still too small to make
proper statements of how reliable our system is.
5.3. System improvements This subchapter summarizes some system improvements that could be done to the system based on
our observations and the conclusions represented in the above subchapter.
Even though, the system fulfills the required functionality, there is still a lot of room for
improvement. For hardware, most of the improvements are related to sensor housing and tubing. As
can be seen from the measurement data shown in the subchapter 5.1, there is still some noise left in
the measurement results. Mainly, the noise comes from the fluctuations of hydrogen peroxide
concentration in the liquid flowing through the sensor housing. Therefore, the sensor housing could
be improved a lot. What we have noticed, it is important to leave enough room in the housing
before the sensor attachment places. This enables the liquid flow to become more static after
leaving the tubes. Also, the surface of the tube inside sensor housing is not so constant as it is in the
plastic tubes and that might also cause some noise to the current signal. One possible way to
improve the housing is to continue the tubes inside the housing and just make small holes to the
tubes for the electrodes. This would make the walls of the sensor housing constant.
Other larger improvement to the hardware would be to have two pumps and two solenoids. This
would separate the liquids totally from each other. The tubes from there could be then just attached
to the sensor housing. This would also probably remove some noise since the liquids would not mix
at all. On this design, however, it would be needed to make sure that there would not be any air in
either of the tubes during the measurement as it would also cause big variance in the liquid flow.
Smaller improvements for the system hardware would be to implement some kind of tube holder
which would enable user to attach the tubes after the pump to the table. Even though the pump is
very good, the design of it still causes the tubes to vibrate. This might cause some variance to the
liquid flow also. We noticed that taping the tubes to the table, reduced some noise from the
measurement.
Other smaller improvements could be to make a more nice-looking box for the electrical
components, implement bigger tanks for the liquids and make some holders to the sensor housing
which would make it easy to attach it to table. During testing we taped the sensor housing to the
table to make sure it would stay still during the measurement.
The software also has lots of things to improve. First the User-Interface could be improved to look
nicer. Especially, the styling and making it even more user-friendly needs a lot of work. That would
require someone who has better eye for this kind of things.
Rest of the software defects are more technical. Due to that, we made a table of bugs that could be
corrected in the software. Table 5 lists the bugs. It has short name for the bug, more detailed
description and tag representing if the bug is more like a new feature or a clear fix to the code. Tag
Defect represents those clear fixes and tag Feature represents that the bug is more like a new feature
for the software.
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Table 5. Table representing known bugs in the software. The Tag of the bug represents if the bug is
more like a new feature or clear defect in the code.
Bug name Bug description Tag
Automate
COM-port
selection
Selecting the COM-port should be automatic or at least it should detect
which COM-ports are in use. Requires more knowledge of Windows USB
Serial communication protocols.
Feature
Improve error
checking of
ArduinoSerial
class
Currently the ArduinoSerial code does not produce any status information
for the user about the status of the connection. Also, it could also produce
error messages to the UI if the connection fails.
Feature
Serial
connection
cannot be re-
established
If user accidentally removes the USB-cable once the application is
running, the serial connection cannot be re-established just by clicking the
Set COM-port -button. User is required to restart the program to re-
establish the connection.
Defect
Use Gamry
Chemical
Toolkit to detect
potentiostat
connection
The software currently assumes that the potentiostat is turned on and
connected properly. Gamry Chemical Toolkit provides special interface
called IGamryDeviceList which could be used to detect the connection.
Defect
Make
communication
between threads
to use events
instead of
polling
Potentiostat control code and user-interface functionalities are now run on
separate threads. The threads currently use polling as communication
method which makes the code hard to read and maintain. Instead of
polling, the events should be used for communication between threads.
Feature
The experiment
parameters in
Auto and
Manual mode
are not
persistent
The parameters are not saved between sessions. When application is
closed, all values are lost and they must be typed again. This is also true
for values in Setup/Settings menu. QSettings might be used for saving the
parameters between settings.
Defect
Different
interval values
for liquid 1 and
2
Currently the intervals for liquid 1 and 2 are equal in auto mode. It makes
sense to add functionality to have intervals of different length.
Feature
Different colors
for data points
in Auto mode
Liquids are switched at constant interval. To better differentiate which
liquid is blocked the data points can have different color.
Feature
Add indication
text to manual
mode that
PSTAT is
initializing
In manual mode, there is no indication that potentiostat is initializing like
in Auto mode. To the lack of time it was not implemented.
Defect
Warning of data
loss when
closing the
application
Application doesn't give warning that data is not saved and might be lost.
There should be indication when pressing X or Exit. Some variable should
be added to indicate whether the data has been saved or not to invoke the
warning.
Defect
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6. Reflection of the Project This chapter summarizes how the project was done compared to the project plan and compared to
the knowledge and skills we had at that phase.
6.1. Reaching objective The expected output of the project consisted of 5 parts: High level functions, the expected user, user
experience, expected performance and demonstration at the end of the project.
The High-level functions consisted of that the test bed for assessing the temporal resolution of
electrochemical sensors is built and it has at least two liquid tanks, places for three electrodes and
controllers for controlling the liquid flow. The system should be connected to PC and potentiostat
and the data from potentiostat is collected to PC software user-interface. The user-interface should
plot a graph of current over time. Based on previous chapters we can say that the high-level
functionalities of this project output were reached.
The expected users should be research groups and students. This output was also reached. The
system will be used by the Aalto University Microsystems research group.
The user experience consisted of user manual which should have all the needed information about
using and set upping the system. This output was also reached and the manual can be found from
Appendix 3: ExperimentControl - User manual.
The expected performance was that the total length of tubes would be minimized, change between
two or more fluids would be flexible and the system should filter away all possible noise. This
output was also reached. The length of the tubes is optimized for the system and the change
between two liquids happens smoothly and automatically (or it can be done very quick manually).
Also, most of the noise is filtered away according to our calculations in subchapter 5.1. The relative
standard deviation is approximately 0.6% which indicates that the fluctuations in the current are
small.
The last part of expected output, demonstration at the end of the project, stated that each part of the
product is well installed, the system is properly tested and the results are documented. Also, the
results should be easy to read from the user-interface of the software. This output was also reached.
We ran 8 measurements with same setup and documented the results. The results can be seen in
Appendix 2: Final test results. The pictures of the results are taken straight from the user-interface
of the software which indicates that the results are also shown clearly on it.
Based on the analysis above and the previous chapters, we can say that the project reached its
objective.
6.2. Timetable The schedule defined in the Project plan was realized mostly, although there were some
readjustments. Despite of some changes, the schedule set out in the initial project plan was held for
the most parts. Table 1 represented earlier in this document, shows the planned schedule. Table 6
represents the comparison between the planned schedule and success of it.
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Table 6. Table representing comparison between the planned schedule and success of it.
Planned task Planned accomplishment date Actual accomplishment date
Project plan 26.1. 26.1.
Ordering hardware parts 24.2. 1.3.
Presentation slides for
Business Aspects seminar
2.3. 2.3.
Business aspects document
submission
10.3. 10.3.
Hardware design ready 1.4. 23.3.
Software design ready 6.4. 31.3.
Integration of hardware and
software ready
13.4. 26.4.
First tests are done 20.4. 26.4.
Final tests are done and
analyzed
1.5. 11.5.
Poster submitted 9.5. 9.5.
Final gala 16.5. 16.5.
Final report submission 29.5. 29.5.
Because of some unpredictable difficulties or limitations, the following milestones were extended a
little, for about one week each: Ordering of the hardware parts, Hardware design, Software design,
Integration, Testing, and Analyzing the results.
In the hardware part, it took more time than expected to choose new electronic components and to
wait for ordering. Most of the hardware parts were newly bought, which was a little unexpected.
Searching optional components on the Internet and determining the best choices were a time-
consuming process, and ordering deliveries also took much time. The delay of the ordering resulted
in the milestone Hardware design delaying as well. Especially, ordering the pump was delayed
since the pump our group originally planned to order could not be bought from China and that
resulted the delay. Integrating software to the hardware was overestimated since it took couple of
days to be completed.
In the software part, using Gamry programming interface was much more difficult than anticipated,
so the milestone Software design was extended. But it was not delayed so much, just only about one
week. Another software task, the user interface design, was relatively easy and it was not a problem.
The delays mentioned above also led to the milestone Integration and Testing changed, which was
postponed 13 days. Finally, the project was accomplished 10 days later than expected. Because the
group originally planned to complete the project 15 days before the Final gala, the group was still
able to finish in time despite the delays.
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Relating to personal work, Table 7 shows workload of every group member compared to the
planned workload.
Table 7. Table representing the workload of group members as planned versus real.
Member Workload estimated (hours) Workload (hours)
Henri 246 274
Borys 227 203
Esko 232 222
Kang 232 208
Qin 233 195
Yi 234 221
Total 1404 1323
As can be seen from the above table, we had planned to use more hours to this project than we did
eventually. However, the workload of project manager exceeded the planned hours. On the other
hand, the project manager was the only person who had written his hours from the very beginning
of this course and therefore there might be some un-written hours in the hours of other team
members. Based on this, we could say that all team members spent about the number of hours they
had planned, except the project manager.
6.3. Risk analysis In the project plan, at least four main risks were presented including absence of group members,
project not finished by deadline, project turning out to be much more difficult as planned and
delayed shipment of materials. During the half year period, some of the risks occurred while some
not. Table 8 shows analysis of how these risks end up in the final results.
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Table 8. How the risks turn out to be
Risk Severity (with
mark)
How considered before Realized
or not
How it turned out to be
Absence of
group
members
Topics cannot be
determined and
the previous
planned schedule
is delayed.
(Moderate)
All members are expected
to attend each group
meeting and working.
Possible absence should be
approved by manager and
instructor for acceptable
reasons. Whoever absent
should spend more effort
in later work to keep up the
pace.
Yes Occasionally team members
were absent from the
meetings or group work
sessions due to acceptable
reasons. However, they
could keep up with the pace
by feedback from other team
members and spending more
time on the project at home.
Project not
finished by
deadline
Project could not
be completed on
time.
(High)
It is likely that some of the
designed functions in the
plan could not be done by
given deadline. The
product parts should,
however, work at least as
planned.
No The final product was
finished before the deadline
and acceptable final results
were acquired as planned.
Project
turns out to
be much
more
difficult
than
planned
Unable to proceed
without clear
solution
(High)
The planned proposal
should be assessed and the
team should receive
enough feedback from
instructor to ensure the
feasibility. Also, informing
instructor as soon as
possible about the
encountered difficulties is
necessary.
No The project was proceeded
without large problems
through all phases. Even
though some small
difficulties came out they
were solved by relying on
the wisdom of our team
members. Besides, we have
minimized this risk by
closely contacting with the
instructor for any decisions
related to project
development.
Delayed
shipment of
materials
Delays the whole
process
(Moderate)
Try to start ordering the
items as soon as possible
thus it requires much more
efforts in the preparation
period. Also, a sharp
deadline for ordering
should be set to avoid the
risk.
Yes A short delay occurred while
ordering the pump since the
university personnel had
difficulties in ordering from
a Chinese webshop. This was
solved by ordering similar
pump from a Finnish
supplier which caused some
delay. However, the group
was able to keep up the
schedule.
Besides, there are several additional risks appeared which we have not planned before. Table 9
demonstrates the severity of the unexpected risks and how we managed to solve them in the end.
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Table 9. Table showing the additional risks appeared during the project.
Risk Severity (with mark) How to solve it
Realized costs exceed the
budget
Budget is limited. If excessive
money is spent on unnecessary
parts, product quality cannot
be guaranteed. The cost-
effectiveness would be quite
low. (Low)
We tried to maximize the use
of current available materials
from previous group but for
some key parts we must spend
the budget to keep higher
product quality.
Background of some group
members is quite thin
It takes too much time for
beginners to learn new things
which would delay the whole
schedule. (Low)
Those group members who are
skilled in basic knowledge of
electronics and programming
help those who have no
previous experience to learn
faster.
6.4. Project Meetings During the project, all members of the team have project meeting once a week in a meeting room at
TUAS building. Hardware team and software teams also held meetings separately. The agenda of
the meeting followed these steps:
Every member must arrive at the specific meeting point at 2 PM. If there is a special case, inform
the manager.
1. The memo-keeper of the meeting is decided. The memo-keeper writes down all the
important issues and decisions represented during the meeting.
2. Everyone makes a couple of minutes presentation in turns in which they will tell what they
have been doing, were there any issues and what they will do next.
3. If there are any difficulties and suggestions, members can propose those after the
presentations.
4. After the presentations, the team will go through the calendar for important dates and
deadlines.
5. After calendar-check, there is time for free discussion and possibility to discuss or work
together in small teams or with the whole team.
6. After the meeting, the memo should be put into the Google Drive folder of the team.
7. Project manager will go through the memo after it has been published to the Drive folder.
Google drive was used in the meetings to keep memo and other documents. Slack was used to
discuss between the meeting. In addition, Trello was also implemented as the tracking of the
process by the team.
We learnt a lot to get an efficient meeting:
The team member must be on time for the meeting.
To save time, agenda meeting template should be prepared in advance.
It is good to manage the time by clock; everyone follow the time of the agenda.
The important discussing point and the diagrams should be prepared in advance to show
them to the other team members.
If the team members could not get agreed solutions, it would be better to continue discussing
after the meeting.
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6.5. Quality management In this section, quality of the project is evaluated. The quality in the project plan consisted 5
aspects: Whether the test bed can work successfully, how well does the test bed work, how easy it is
to use, how well is the noise handled and can the group give a satisfactory analysis based on the
data obtained.
The first aspect is mainly related to the idea that the group manages to create a working test bed
with the functionalities planned. Our conclusions indicate that this was achieved since the test bed
can be used to gain the required data. Also, the most of the designed functionalities were
implemented: The change between liquids happens fast. The pump produces static flow of liquid.
The sensor housing covers the electrodes but does not store liquid itself (makes changing between
the two liquids faster). Also, the software represents the data from the potentiostat in real-time and
the data can be downloaded as a CSV-file (comma-separated values).
The second aspect of quality is related more closely to the functionalities of the test bed and the
quality of the measurement data. The noise is reduced a lot according to the test results (see chapter
5. Test results and analysis and Appendix 2: Final test results). The test data from the measurement
is obtained in real-time and the data can be also downloaded from the user-interface as a CSV-file
(comma separated value). Unfortunately, the support for more than two fluids was not implemented
due to time constraints.
The third aspect of quality addresses the user-friendliness of the system. The user-interface is
developed simple and the buttons and functionalities are clear. Set upping the system is also easy if
the user has any background knowledge of using and set upping the potentiostat. Making sure that
the alligator clips of the potentiostat do not touch each other during the measurement is the hardest
part of the setup. Also, installing the computer software has been made easy with a Windows-based
installer.
The system can be used under two different modes: Auto and Manual. These make the usage of the
system flexible and easy. In Auto mode, experiments can be done automatically after several input
settings. Users can also manually control the pump, the potentiostat, and the valves under Manual
mode. The user interface clearly and concisely shows necessary buttons and input boxes of settings.
It is worth mentioning that data can be presented in real-time in the user interface, which is
convenient for observing data variation during experiments.
A User Manual document is also provided (see Appendix 3: ExperimentControl - User manual) to
give users a guide on how to use the system.
The fourth aspect of quality is again related to the quality of the measurement data. This has been
put as a separate quality criteria since reducing the noise to minimum was our main goal in this
project. Sufficient quality is easily obtained if the user has properly setup the system (i.e. the
alligator clips of the potentiostat are not touching each other and the pump tubes and the sensor
housing are taped to the table to reduce any vibrations caused by the pump). Based on our
measurement results and calculations (see chapter 5. Test results and analysis) the noise is
minimized a lot which makes this quality aspect successful.
The fifth and the final quality aspect is related to the analysis of our measurement data. The main
goal of the analysis is to discover how the temporal resolution can be calculated from the data
obtained from the measurements. The group managed to discover proper methods for that. The
details of this analysis can be found from the chapter 5. Test results and analysis.
Page 33 of 37
Based on the analysis of the 5 quality aspects, the quality of this project was good. The system
works as expected and it can be used to obtain accurate measurement data with little noise. The
system is easy to setup and the user-interface is intuitive to use. Also, the methods of calculating the
temporal resolution from the measurement data were discovered.
6.6. System design This subchapter describes the changes made to the system design compared to the one planned.
The original idea of the solution was kept. The basic structure of the system was done as planned:
The system has at least 2 liquid tanks, valve for controlling the liquids, pump, microcontroller,
sensor housing for at least for 3 electrodes, PC software and waste tank. However, in the plan the
idea was to make the system to support any number of liquids but during the development phase it
was realized that support for more than 2 liquids would require more valves. Due to the high cost of
valves, our team decided to go only with one valve and therefore supporting only 2 liquids was
possible. Figure 1 in chapter 3.1 is taken from our project plan and it is representing the planned
system design. In the Figure 1 the potentiostat is also shown as variable power source and current
meter markings. The power source is left also away in this figure. In chapter 4, the Figure 11
represents the final design of the system. In Figure 11, the potentiostat is left out and the power
source is added.
6.7. Cost plan This subchapter represents the comparison of the planned costs and the real costs. The planned costs
are shown in Table 2 represented earlier in this document.
A pump, a power source, an Arduino and a set of valves were ordered. The total cost of the project
was 485.99 euros, which went around 26 euros over the budget. Table 10 shows a summary of the
costs. The reason for this was mainly that we had to replace almost all the parts except
microcontroller. From Table 10 can be seen that the most expensive part was the pump. Our idea
from the beginning was that the pump the previous team used would cause the most of the noise in
the measurement and therefore, we wanted to change that to better one. Another expensive part was
the solenoid valve. It also had to be changed since the pump was too powerful and the previous
valve would have leaked.
Table 10. Table representing comparison between estimated and real costs.
Device Estimated cost (EUR) Real cost (EUR) Notes
Liquid tanks 10-20 0.00 2 tanks (from last year)
Sensor housing 30 0.00 No direct costs for us
Pump (+Tubes) 50-100 260.05
Enclosure 9.90 9.90
Microcontroller 50 0.00 Arduino (from last year)
Valve 50-100 113.00
Other costs 130-150 102.94 Motor control shield, jump
wires, power source
Total 320-450 485.89
Page 34 of 37
The overestimated costs consisted of liquid tanks and Arduino board. The group used the existing
liquid tanks and Arduino, and made a new sensor housing by 3D printer, which can be used in the
Aalto Industrial Internet Campus for free. So, there were no real costs on these three items.
The underestimated costs consisted of the solenoid valve and the pump. The real cost of the valve
was a little over budget. Pump (+tubes) was the most expensive part and the most underestimated
cost. The new pump exceeded budget about 160 euros, which is the main reason why the total real
costs a bit exceeded.
The costs of the other purchased items, including motor control shield, jump wires and power
source, met the estimation.
Page 35 of 37
7. Discussion and Conclusions All members of the team have acquired new skills. Working in a team was considered very
important by almost all members. Few people on the team had previous experience working on a
project and found this novel experience important. Qt Framework and C++ programming language
was used a lot in implementing user interface. Members of the software team didn't have solid
knowledge of C++ and Qt. Basic knowledge about Qt and C++ was gained. We had an
international, diverse team with students from Finland, Ukraine and China. It exposed team
members to different cultures. Our instructor taught us basic rules and some techniques when
working in the chemistry lab. The hardware team learned how to use Arduino to control pump and
solenoid and different aspects of building electronic device to control the flow of liquid. The course
was considered by all useful but schedule a bit too tight.
Henri:
This project has been my first project as an actual project manager. In many school-related
projects I have of course been the responsible-person who has made sure everything gets done as it
should but that has always been just a silent contract between me and other team members. This
time I was chosen to be the real responsible person of this project. It has not of course been an easy
task but thanks to the other members of our team, it has been a great experience. I have learnt a lot
about leading motivated individuals and learnt how people like that should be motivated when
things have not gone so well. I have also learnt that some tasks should be allocated to others even if
they would seem an easy and quick task for myself. I think my biggest weakness in this project was
that I wanted to be involved very strictly in everything and that caused me to maybe worry too much
about this project (in a long time it might have caused a burn-out).
Most of my learning experience has been related to leading people and managing the project. But
there are also other things, for example I want to thank especially Borys for teaching me how to use
Qt Framework and giving me good tips about coding C++. I also learnt a bit about
electrochemistry and working in the lab environment from our instructor Noora.
In the end this project has given me a lot of good experience. When reflecting my work, I would say
that my weakness was what I mentioned before but when considering the tight schedule, we had, I
do not think it was a bad thing that I was involved strictly in every part of the project.
Borys:
During the course, I saw how project management tools like Trello might be useful for tracking and
creation of tasks related to the project. I was skeptical of how useful such tools are before I started
to use them for the project. One big thing that consumed most of my time was implementing control
program for the potentiostat and user-interface for inputting controls parameters and presenting
data to the user of our ExperimentControl program. For that task, I had to learn usage of Qt
software libraries and common software design patterns.
The most import things that I knew before, but the experience gained during the different stages of
the course has reinforced is importance of achieving the goals via process of trial and error and not
give up when presented with the obstacles that might seem impenetrable.
Kang:
By completing this project with a team, I have acquired a lot of useful skills which would be
beneficial for my future career. I am a member of hardware team in this project. During the process
of implementing hardware parts, I have learned how to use Arduino board to control an electronic
system as well as how to assemble a hardware system from other team members. What is more
Page 36 of 37
important is I have experienced a whole process of doing a team project from the beginning to the
end. This was a wonderful experience for me to practice team spirit and cooperation. Thanks for
every team member and everyone’s distribution to this project!
Qin:
During the project, I mainly did the task user interface design, which I had never learnt about that
before. It was a good experience for me to learn a skill by myself, and now I master basic method
about how to design a UI with Qt. I also gained valuable experience of doing a project in a team,
learning how to use Git, Trello and Slack to do cooperation work. In addition, I learnt more about
microcontroller, programming and how to apply software part to equipment.
Yi:
As a member of this talented team, I learned a lot in this project. Firstly, I learn how to decompose
a target, then finish it step by step. Secondly, new tools like Trello, Slack, Qt, which is introduced by
other members, are very useful in either project tracking or saving files. What is more, I found my
weakness in programming abilities. At last, it is a good experience to work in an international team,
I gain a lot in communication ability.
Esko:
During the project, I learnt much about project work. Electrochemistry was completely new area
for me, which required a lot of learning. I worked in hardware team and I arranged our hardware
meetings which gave me valuable communication skills. I made hardware code implementations in
our hardware team (a pump and a relay control). We also ordered different hardware parts (circuit
boards, pumps, etc.) based on their datasheets, which was useful experience. Because of the budget
limit, we had to implement very accurate specifications for the hardware parts based on their
datasheets. This project gave a lot of useful practical skills too. We made a lot of practical issues,
like assembling the whole system and so on. The analysis of the results taught me useful statistical
analysis methods. During the project, I also realized importance of project work tools like Git and
Trello.
Page 37 of 37
List of Appendixes
Appendix 1: Project plan
Appendix 2: Final test results
Appendix 3: ExperimentControl - User manual
References [1] Arthur J. L. Cooper & Thomas M. Jeitner “Central Role of Glutamate Metabolism in the
Maintenance of Nitrogen Homeostasis in Normal and
Hyperammonemic Brain”, New York Medical College, New York, 2016
[2] Rochelle Ford, Susan J. Quinn and Robert D. O’Neill “Characterization of Biosensors
Based on Recombinant Glutamate Oxidase: Comparison of Crosslinking
[3] Olli kotiranta “Amperometrisen välittäjäaineanturin karakterisointilaitteiston
suunnittelu ja toteutus ” Master’s thesis, Aalto University, Finland, 2012
[4] Noora Tujunen “Amperometric measurement of glutamate” Master’s thesis, Aalto
University, Finland, 2013
[5] Timotheus Budisantoso, Harumi Harada and Naomi Kamasawa “Evaluation of
glutamate concentration transient in the synaptic cleft of the rat calyx of Held” Journal of
Physiology 591(1):219, 2013
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