Calorimetric differential pressure sensor with high sensitivity for hydrodynamic perception

Accurate perception of hydrodynamic information is crucial for intelligent navigation and control of underwater robotics in challenging underwater environments. Current diaphragm-based differential pressure sensors are generally constrained by limited resolution for hydrodynamic perception. Here, we present a high-sensitivity calorimetric differential pressure sensor featured with precisely designed calorimetric components located on cantilever beams. The proposed sensor achieves an impressive underwater differential pressure resolution of 18.9 mPa and a repeatability standard deviation of 0.38%. By integrating a sensor array consisting of three such sensors into an underwater robotic model, the velocity and yaw angle were estimated simultaneously with average solution errors of 2.9 mm·s^-1 and 0.94°, respectively. Underwater obstacles can be recognized with an accuracy of 97.5% by perceiving hydrodynamic variations in the Kármán vortex street due to its high sensitivity. Overall, the proposed sensor shows many potential applications in underwater flow sensing and the control of underwater robotics.