S135Abstracts / Comparative Biochemistry and Physiology, Part A 146 (2007) S129–S141

pressure inside the pressure chamber which is measured by themechanosensitive neuron.

doi:10.1016/j.cbpa.2007.01.259

A7.20The morphology and mechanics of Orthopteroideamechanosensors

E. Johnson, C. Santulli, G. Jeronimidis, (University ofReading, United Kingdom)

Crickets, and other orthopteroidea, possess one of the mostsensitive hair-based sensory systems found in nature. The arrayof mechanosensors, located on the cerci, can “measure” smallchanges in air flow, enabling the cricket to detect and escapefrom approaching predators. The morphology and mechanics ofthe air-flow sensory system has been studied in order to identifycommon principles underlying the use of such a solution innature and to make those principles available for the design ofbio-inspired engineering applications.Morphological details about the single hair and array system,were determined using a combination of imaging techniquesthat include Scanning Electron Microscopy and ConfocalMicroscopy. Mechanically, the hair-socket arrangementbehaves as an auditory system, able to respond to externalvibrations at up to 10 kHz. Scanning Laser Vibrometry (SLV)was used to determine the velocity and displacement of the hairin response to a white noise “chirp“ produced through avibrating membrane. The deflection patterns observed in thehairs appear to be mixed-modes showing bending and rotation,particularly at low frequencies, and an effect of hair length wasalso observed. Vibration peaks presented by the stimulus platehave been clearly detected by the hairs and the measuredangular displacement of the hairs fell between 0.005 and 0.01°.The ability to artificially replicate this highly sensitive system,will open the door to engineering solutions such as MEMShairs. Applications for this developing technology includecochlear implants and air velocity detectors with a high degreeof in-built redundancy.

doi:10.1016/j.cbpa.2007.01.260

A7.21Opportunities and challenges for obtaining effectivelubricated engineering systems inspired by the lubricationof synovial joints

A. Morina, T. Liskiewicz, Y. Yan, A. Neville, (University ofLeeds, United Kingdom)

The application of tribology in medicine and biology is agrowing and rapidly expanding field, mainly driven by the

increasing need for the development of prosthetic devices toreplace diseased tissues and organs. In this study biomimeticsand bioinspiration of effective natural lubricated systems andformation of unique tribologic materials are applied towardsimprovement of engineering tribology systems. This is of greatimportance now and in the future since lubricating surfaces tominimise wear and friction using chemical species which haveno harmful effects on the environment is an immense challengefor engine oil formulators, the tier two components suppliersand the original equipment manufacturers (OEMs). Additives tocontrol friction and reduce wear are commonly used and thesefunction by forming a nanometre scale film (the tribofilm) onrubbing or sliding surfaces. This film has several key features: itforms spontaneously on rubbing, it has a nanostructuredcomposition, it is self-healing and it is smart. To achieve allof these functions from “green” compounds is an immensechallenge for lubricant additive formulators.As a novel approach to lubricant additive design we are currentlyinvestigating the feasibility of using a biomimetic approach todevelop novel lubrication strategies and in this paper we willfocus on the potential of development of effective lubricatedsystem inspired by the lubrication of natural synovial joints.Natural synovial joints are able to articulate freely withextremely low friction and wear for over 75 million loadingcycles in a lifetime. In this paper the joint biomechanics,properties of the materials and fluids involved and challengesrelated to the transfer of obtained knowledge towards producingequivalent engineering systems will be discussed. The materialproperties, surfaces and interfaces needed to replicate thefunctionality mode of this system will also be discussed.

doi:10.1016/j.cbpa.2007.01.261

A7.22Bio-inspired medical technology

P. Breedveld, (Delft University of Technology, TheNetherlands)

The department Bio-Mechanical Engineering of Delft Uni-versity of Technology uses nature to develop novel surgicalinstruments for medical applications such as minimally invasivesurgery and colonoscopy. The research is carried out in closeco-operation with surgeons and biologists.Minimally invasive surgery is carried out through very smallincisions in the skin to reduce damage to healthy tissues. Theincisions, however, hamper the instrument movements, makingit difficult to approach organs from different sides. Steerableinstruments can solve this problem but are complex and difficultto miniaturize. At TU Delft, a novel steerable mechanism basedon tentacles of squid has been developed. The mechanism isvery simple and can be easily miniaturized up to very smalldiameters. The mechanism is patented and being commercia-lized into a range of steerable instruments for laparoscopy, eye-surgery and catheter interventions.