Arrays of EAP micro-actuators for single-cell stretching applications

Abstract

Mechanical stimuli are critical for the development and maintenance ofmost tissues such as muscles, cartilage, bones and blood vessels. Thecommercially available cell culture systems replicating the in vivoenvironment are typically based on simple membrane cell-stretchingequipment, which can only measure the average response of large coloniesof cells over areas of greater than one cm(2). We present here theconceptual design and the complete fabrication process of an array of128 Electro-Active Polymer (EAP) micro-actuators which are uni-axiallystretched and hence used to impose unidirectional strain on singlecells, make it feasible to do experiments on the cytomechanics ofindividual cells. The Finite Element Method is employed to study theeffect of different design parameters on achievable strain, leading tothe optimized design. Compliant gold electrodes are deposited bylow-energy ion implantation on both sides of a PDMS membrane, as thistechnique allows making electrodes that support large strain withminimal stiffening of the elastomer. The membrane is bonded to a rigidsupport, leading to an array of 100x100 mu m(2) EAP actuators.