Abstract
A micro gripper with high-stiffness was designed and fabricated for handling of thin bio-sheets. Flash-evaporated thick (30 μm) TiNiCu shape memory alloy (SMA) film was employed to obtain sufficently stiff gripper. Thin film circuits of Pt heaters and Pt-Au thermo couple were integrated on the SMA micro gripper. The integrated heaters were designed so that the gripper can be reversibly driven between holding and releasing position. The SMA micro-gripper was closed at room temperature because the inner and outer arms of the gripper were similarly deflected by intrinsic stress of the SMA thick film. The outer arm of the gripper was reversibly deformed to 100μm in the direction of gripper opening when it was heated above phase transformation temperature. Spring constant of the gripper inner arm was about 30 N/m corresponding to a gripping force of 3 mN when 100μm thick sheet is held by the gripper.
