Normally Closed Microgrippers Based on Diamond Like Carbon Structures
Highly compressively stressed diamond-like carbon and polymer films were used to fabricate normally closed microgrippers with diameters as small as 30~40μm. The microgrippers consisted of a DLC layer of 30-50nm, a thin Al layer of 40nm as a heater and an SU8 layer of 250~500nm, and were fabricated by a self-aligned two-mask process. Electrical tests and nonelectrical tests on a Peltier device confirmed the devices have an operation temperature of ~100°C for an opening angle of 90°, much lower than the ~400°C needed for previously fabricated Ni/DLC microgrippers. This value is consistent with finite element modelling and analytical calculation. The power needed to open the microgripper was only ~10 mW, less than half of those used for the previous Ni/DLC microgrippers. It has been successfully demonstrated that the microgrippers can be used to capture and confine micro-objects using microbeads for the tests.
P. VINCENZINI and E. CAPPELLI
J.K. Luo et al., "Normally Closed Microgrippers Based on Diamond Like Carbon Structures", Advances in Science and Technology, Vol. 48, pp. 133-141, 2006