Nano-Optomechanical Resonators Based Graphene/Au Membrane for Current Sensing

The monitoring of electric current is essential to ensuring the reliable operation of power systems and electronic equipment. The present study demonstrates an optomechanical cavity-based resonator suitable for current sensing. The proposed device consists of a suspended graphene/Au membrane supported by a ceramic ferrule with a bore diameter of approximately 125 µm and incorporates optical actuation and detection processes. The present sensor exhibits high current sensitivities of approximately 7.91 and 18.04 Hz/mA ² when monitoring the resonant frequency at first and second-order vibrational modes. This optomechanical current sensor operates for the first time in the 100 mA range, an advance of more than two orders of magnitude on the sole previously reported cavity optomechanical current sensor. Moreover, the current sensor shows a short response time of ∼2 ms and provides the additional advantages of low power consumption and a compact structure. This device is expected to have applications in high-precision current and magnetic field sensing.