Reporter:

DR. Wenhui Wang PhD (Lecturer, Mechanical Engineering, University of Canterbury, New Zealand)

Title:

PDMS microdevices for micro-nano scale biomechanical measurements.

Abstract:

Biomechanical (or force) measurements at cellular and animal levels have important implications in biological studies.  At the micro-nano scale, force measurements are often conducted using transducers based on microelectro-mechanical systems (MEMS), such as capacitive force sensors and piezoresistive cantilevers. Recently, an innovative alternative approach employing microfabricated polydimethylsiloxane(PDMS) post/pillar structures as force transducers was reported to visually measure traction forces generated by adherent cells. Unlike flexible thin substrates, the post/pillar structure does not require heavily complex computations for calculating traction forces. Compared to silicon-based MEMS devices, PDMS-based devices are biocompatible and can be readily fabricated using soft-lithography techniques.

This talk presents two micropillar-based PDMS devices which are suitable for measuring cellular force of suspended cells (such as zebrafish embryos) and dynamic force of small animals (such as C.elegans). Both microdevices essentially have an array of protruding cantilever-like pillars which deflect correspondingly due to the force to be measured. The deflection of pillars is visually tracked with sub-pixel accuracy by an imaging system and force is accordingly resolved from the deflection according to an established deflection-force mechanism. These PDMS microdevices under current configuration, coupled with computer vision, are capable of measuring cellular force at a resolution of 3.7uN, and C.elegans motion force at a resolution of 1.5uN, respectively.

Time:

AM10:00, 17 Nov 2009

Place:

The third flood Meeting Room, Building R