Performance evaluation of a curved electrode actuator fabricated without gold/chromium conductive layers

Abstract

Curved electrode actuators displace on the order of a biological cell diameter at low actuation voltages, making them a potential candidate for probing and micromanipulation of cells in an underwater, closed microenvironment. Here, a closed microenvironment is formed by bonding a Polydimethylsiloxane-based cap-like structure to the actuator; however, the presence of Au/Cr conductive layers on the actuator reduce the available silicon surface area of the actuator-resulting in poor adhesion. Therefore, we propose to fabricate the actuators without these conductive layers. In this paper, we demonstrate the absence of these layers has a minimal effect on the actuator's peak-to-peak displacement and force. The actuator achieves the following performance metrics: large displacement (1-10 mu m) and force (1-21.5 mu N) range; broad frequency range (1-500 Hz); and low actuation voltages (0-8 V) in viscous media that are necessary for cell probing and micromanipulation applications.