Graphene Oxide Nanofabricated Ultrasonic Transducers (GO-NUTs)

Graphene Oxide Nanofabricated Ultrasonic Transducers (GO-NUTs) based on porous electrodes immersed in ionic liquid electrolyte, which use the vibration of the compressible electric double layer to transmit and receive ultrasound with signal level several order of magnitude higher than existing capacitive transducers are introduced. A simple, rapid and scalable method to reduce graphene oxide (GO) by Laser Lightscribe annealing was also demonstrated. The reduced graphene oxide (rGO) for scalable and rapid production was then fabricated to graphene-based ultrasonic transducers which exhibit supercapacitor characteristics. The vibration of ions at the electric double layer (EDL) on the interface of the multi-layer rGO electrode that immersed in liquid electrolyte can simulate the flexible vibrating membrane of capacitive micromachined ultrasonic transducers to match the acoustic impedance of the soft tissue. The amplitude and frequency response to ultrasonic source were measured by oscilloscope and analyzed by MatLab. The capacitance, potential, and frequency response measurement of the GO-NUTs had shown the functionality of the device and suggested it can be used in the high frequency range. The testing result also showed that the reduced graphene oxide had advantages over the material used in traditional piezoelectric ultrasonic transducer. The GO-NUTs could also be further fabricated to interdigitated and array patterns simply by Laser Lightscribe CD/DVD drive and software.