Stiffness characterisation of microcantilevers based on conductingpolymers

摘要

The object of this paper is to characterise the stiffness of microfabricated cantilevers consisting of two electroactivepolymer (polypyrrole (PPy)) layers, and two gold layers with a negligible thickness and a layer of porous polyvinylidenefluoride (PVDF), which serves as a backing layer and electrolyte storage tank. This composite cantilever structure isused as polymer actuators or famously known as artificial muscles when tailored appropriately. The polymermicroactuators considered in this study, which were fabricated using a laser ablation technique, could operate both inaqueous and non-aqueous media. The stiffness characterization of the microactuators is critical to assess their suitabilityto numerous applications including the micromanipulation of living cells, bio-analytical nanosystems, datastorage, lab-on-chip, microvalve, microswitch, microshutter, cantilever light modulators, micro-optical instrumentation, artificialmuscles for micro and macro robotic sytems and similar. The stiffness measurement method followed in this study is astatic deflection measurement method, using an atomic force microscope (AFM). The stiffness constants of themicroactuators while they were in passive (no electrochemical activation) and active (electrochemically activated) stateswere measured separately, and their statistical comparison was provided. The possible error sources for the stiffnessmeasurement method are elaborated.