Study of photo-driven lever beams fabricated by two-photon polymerization for sensor applications

We report on a novel type of photo-driven lever beam fabricated by two-photon polymerization, which can be used as microsensors in biomechanics measurement by use of optical tweezers. Optical tweezers is an effective tool for manipulating dielectric microspheres and biological cells. This technique has opened up a wide range of applications such as biomedical engineering, biophysics, and bio-MEMs. By two-photon polymerization (TPP) method, microfabrication of 3D polymer objects can be readily obtained. This technique is widely used to produce arbitrary complex microstructures. Our lever beam is composed of a ball mass, a lever beam, and an arch. The optical tweezers is applied to trap the ball mass which is placed at the end of lever beam. Under the dragging, the lever beam simultaneously turns and results a lever torque, so the relationship between dragging force and spring stiffness can be determined. Experimental results indicate that optical tweezers can successfully drive the lever beam. The feasibility experiment will be completed after an optimal spring shape is modified. Eventually this study will provide a novel technique for the sensing application in the investigation of lab-on-a-chip.