Waterproof Pressure Sensor Leveraging Nano-/Microdeformation of Microstructure under Pressure for Collecting Wide-Range Human Physiological Signals Underwater Stably.

Underwater physical signal collection is crucial for helping athletes evaluate health and optimize training methods. However, it is difficult for existing underwater devices to simultaneously collect stable and accurate subtle pulse signals and large motions in complex water environments. Herein, a flexible, waterproof, and stable underwater human physical signal collection system based on a flexible micropillar double-layer pressure sensor was proposed. The developed sensor is integrated with a micropillar sensing layer and packaging layer, which exhibit a dual-mode sensing range that includes subtle and high pressure with a rapid response. The sensing layer provides wide-range deformation for improving the sensing performance; the packaging layer reduces the influence of water flow on the sensor when sensing subtle pressure underwater, which provides support for the microstructure when it senses high pressure to enhance the sensing performance. The sensor can accurately recognize both subtle pulse vibrations and large-scale muscle expansion-contraction signals in water. Therefore, an underwater physical signal collection device (UPCD) was constructed with a micropillar sensor and an information storage circuit board. The status of an underwater athlete can be estimated through a machine learning method by analyzing the data collected from the UPCD, which can recognize the training and physical conditions and further assist in optimizing the training method.