Design and Analysis of Actuated Microneedles for Robotic Manipulation

We present the design of a MEMS based single-unit actuator consisting of a single microneedle with 3D mobility. The four-sided single-unit actuator (4SA) microrobot design can achieve an in-plane actuation (x, y) of 76 μm (±38 μm) at 160 V and an out-of-plane actuation (z) of more than 6.5 μm at 35 V. The mechanical stress developed within the operational range is between 0.08 to 0.5 percent of the yield strength of silicon i.e. 7000 MPa. We discuss both the analytical modeling and finite element analysis (FEA) simulation of the design based on the range of dimensions analyzed for the individual actuator components. Our primary goal is to integrate multiple actuators into a parallel architecture for independent actuation of multiple microneedles for targeted micro- and nano-robotic manipulation tasks, such as single-cell analyses. We have also successfully fabricated sample 4SA microrobot without the microneedle as a pre-cursor to experimenting with our future advanced design of microrobots. We demonstrate successfully the 3D actuation of the 4SA microrobot of up to 10 μm at 120 V (in-plane) and more than 0.5 μm at 600 V (out-of-plane) with minimum decoupling.Copyright © 2014 by ASME