Ultraminiature otolith-inspired microcantilever sensor based on a heterograft self-growing method for micro-vibration sensing and vibration mode analysis

Inspired by the otolith structure in biology, an ultraminiature otolith-inspired microcantilever sensor was presented and applied to micro-vibration sensing and vibration mode analysis. By imitating the grafting and transfer processes in phytology, the fabrication method proposed for the first time, to our knowledge, can realize a micron-scale functionalized cantilever using only a common ultraviolet laser. The sensor is tiny in size and has an ultrahigh sensitivity of 7123 mV/g. Due to its outstanding performance, this structure enables the perception of minute vibrations and detailed recognition. Combining the recognition ability of the sensor with the simplest actions of tapping and patting, an ordinary desktop can be transformed into a Morse code transmitter that is workable on the entire area. Furthermore, by integrating the sensor with time-frequency analysis and machine learning techniques, it is possible to classify and identify multiple vibration modes occurring on the ground. The ultraminiature vibration sensor, as well as the fabrication method, provides a novel solution for low-cost and high-performance optical micro-nano probes.