Design and fabrication of a UV-LIGA compliant micrograsper for ophthalmic surgery

A miniaturized grasping tool was designed and fabricated for use in ophthalmic procedures. The grasping travel range was optimized to have a 2-4 mm jaw spacing in the open position which is a requirement for ophthalmic surgery. Design optimization approaches were utilized to design a grasper which can tolerate large displacements without fracture. The device was fabricated using the UV-LIGA technique using SU-8 photoresist as a molding template. After the device was fabricated it was integrated with a 20-gauge cylindrical package which guides the device's movement. The packaging tube is used to manipulate the device. In the device's natural position the jaws remain open. As the device is pulled through the tube, the tube's wall forces the jaws closed for a grasping motion. The pull-off force of the micrograpser during grasping motion was measured and the value is comparable value to that of a commercial micrograpser developed by Alcon Manufacturing Ltd. using traditional fabrication techniques. A microcutter was also developed by substituting the grasping jaws of the micrograsper with sharp blades. Ex vivo tests were further conducted in order to evaluate the performance of the miniaturized instruments for manipulating and cutting objects similar to those encountered during an ophthalmic procedure.