A prototype of thermally actuated microscale scissors with a sharpened blade

This paper presents a prototype of thermally actuated microscale scissors. The scissors have a similar structure to micro-grippers except that the scissors tip has a sharpened blade. With this blade, the scissors aim to chop soft objects like biological samples while micro-grippers are designed to handle or manipulate them. A movable beam with the blade are hinged to a base structure while another beam are fixed to the base structure. A disk are hinged both to the base structure and to the bottom of the movable beam. The disk expands when heated, and the disk pushes and slants the movable beam to close the scissors. The scissors were made of single layered SU-8 and fabricated with an ordinal photolithography technique except for the blade tip. The blade tip was covered with the additional mask to prevent the first exposure, and then it was exposed in inclined UV light. The scissors were actuated by heating its expanding disk with a focused IR laser. Experimental results showed that higher laser output results in larger scissors' displacement. In the cutting trial of a tofu film, the microscale scissors made a sharp crack on the surface of the tofu film.