InterMicroNano Summer Undergraduate Research Experience IMSURE Fabrication and
Inter-Micro/Nano Summer Undergraduate Research Experience (IMSURE) Fabrication and Design Considerations for Microfluidics -based Tactile Sensors for Prosthetic Hand Shehreen Dheda Faculty Mentor: Abraham P. Lee, Ph. D Graduate Mentor: Jeffrey S. Fisher Department of Biomedical Engineering, University of California, Irvine August 31, 2006
Outline: l l l Biological mechanoreceptors of the human hand Our synthetic tactile sensor design Device manufacturing and characterization techniques and their outcomes Conclusions Acknowledgements
Biological Mechanoreceptors of the Human Hand Slowly Adapting (SA) afferents (RA) (SA) (RA) Kandel, E. The Principles of Neural Sciences, 2000 (SA) Rapidly Adapting (RA) afferents
Synthetic Tactile Sensor Design mimics Merkel cell-slowly adapting type 1 (SA-1) afferents mimics Meissner corpuscles-rapidly adapting (RA) afferents
Device Components l Materials used are poly(dimethylsiloxane) (PDMS) and polyimide or glass. Reservoir shape molded into PDMS, and electrodes laid onto the polyimide/glass.
Filling Techniques Three different methods have been investigated: 1. Syringe 2. Pump 3. Channel Outgas Technique (COT) (Monahan et al, 2001) Monahan et al. , Anal. Chem. 73: 3193 -7 2001
Issues with Filling Techniques l Air bubbles formed in reservoir with syringe and pump methods. l For pump and COT method, sealing of PDMS where holes are made is necessary. COT needs modification to allow for selective filling. l
Fluid Loss from the Devices were filled using a syringe and sealed with uncured PDMS. They were kept at room temperature for a number of weeks and the loss of fluid out of the devices was tracked. Air bubbles on days 1, day 8 and day 16 respectively.
Mechanical Modeling of Sensor Stress within PDMS layer Fluid flow inside reservoir
Conclusions l l l Improvements to existing filling techniques or more techniques need to be explored. Fluid loss is possible, so prevention is needed. Fluid flow from reservoir is linear to applied pressure. Other geometries and models should also be investigated.
Acknowledgements: l l l A. P. Lee, Ph. D Jeffrey S. Fisher Wei-Yu (Tim) Tseng Undergraduate Research Opportunity Program, UROP National Science Foundation, NSF
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