Electrothermally activated SU-8 microgripper for single cell manipulation in solution

The development of a SU-8-based microgripper that can operate in physiological ionic solutions is presented. The electrothermally activated polymer gripper consists of two hot-and-cold-arm actuators that are fabricated in a two-mask surface micromachining process. The high thermal expansion coefficient of SU-8 (52 ppm/degrees C) compared to silicon and metals, allows the actuation of the microgripper with small average temperature elevations (10 - 32 degrees C) at low voltages (1-2 V). The polymer microgripper can be used for the manipulation of single cells and other biological species in solution with minimal undesired interactions.