Optomechanical Switches and Logic Gate Functions Based on GaN-on-Sapphire Devices Integrated With PDMS Membranes

In this letter, the millimeter-sized optomechanical switches are fabricated based on GaN-on-sapphire devices integrated with PDMS membranes. The mechanically deformable PDMS membrane can effectively introduce optical changes at the sapphire boundary of the GaN device during force loading. The devices with oil-filled and air cavities can exhibit increasing and decreasing photocurrent trends in response to the applied force, respectively, making them function as normally-on and normally-off switches. By pairing the switches in series/parallel connections, the logic gate functions of AND, OR, NAND, and NOR are demonstrated, paving the way for the potential development of force-gated logic circuits.