Detection ofHarmful Algal Blooms (HAB)

Created By: Matthew BarbozaSupervising Professor: Dr. Sungyong Jung

Analog Mixed signal Integrated Circuits (AMIC)

Purpose• Main Problem: Harmful Algal Blooms (HAB’s)

posing a threat to environment and local population.• Current detection methods

o Manual Sampling and Testingo accurate analysis – small areas, time consuming, after the

evento Aerial Scanningo large area scan – uncertainties, may not be real-time

• Proposed Solution: Submerged array of sensors to provide real-time, large area identification for early warning and treatment

In Situ Wireless Sensing Network

(WSN)

• Qualitative and quantitative analysis.

• Easy to cover vast space and time.

• Real time and in situ monitoring.

• Early warning system.

Microsystinsensors

Overview• Background:

o Harmful Algal Bloomso Immunoassayso Optical Electronics, laser-diodes and PIN photodiodeso Transimpedance Amplifiers

• Set-up• Devices• Progress

Harmful AlgalBlooms (HAB)

• What is a HAB?o Sudden increase of marine microorganism population

• algae, bacteria

• Why is it “harmful”o Hypoxic conditions (little oxygen)o Toxins

• e.g. Microcystin LR produced by Microsystis Aerugenosa

Immunoassay

• A technique of identifying a substance by its ability to bind to an antibody. - Collins English Dictionary

Laser Diodes

• Emission of light due to electron-hole recombination• Monochromatic• Narrow beam

Photodiode• Incident light causes electron-hole pairs• Carriers are swept across depletion region• Increase in reverse current• Current proportional to incident light• PIN , P-type, Intrinsic, N-type

Transimpedance Amplifier (TIA)

• Input current signal Ii, output voltage signal Vo• Amplifier gain is Vo/Ii (ohms)

Immunoassay

Antibody – AntigenBonding Site

Laser Diode

PhotodetectorAmplifier

Circuit

Microcontroller

Analog to DigitalConverter

WirelessTransmitter

Digitally ControlledPulsing

CommunicationProtocol

Memory

Devices• FDS1010 – Photodetector – Thorlabs• D7805I – Laser Diode – Digikey• OPA380 – Transimpedance amplifier – Digikey• TiWi5 – Wireless• dsPIC33FJ128MC802 – Microcontroller – Mouser

Progress• Microcontroller Configuration

o 25.3 ns Instruction cycle (98.8% of 40 MIPS)o 39525652 Timer Interrupt ( ~ 1 second)o Single, 10-bit, ADC conversion

• K. G. Sellner et al., “Harmful Algal Blooms: Causes, Impact, and Detection” in Society for Industrial Microbiology, Copyright © 2003 EBSCO Publishing, DOI 10.1007/s10295-003-0074-9