Each sensor consists of multiple micro-strain gauges containing a stressed layer of silicon dioxide that, after the stress is released by dissolving a sacrificial layer, deforms into a three-dimensional geometry. Thin metal or alloy wires on the strain gauges can measure normal force, shear force and temperature. Because the sensors are made by standard processes used in microelectromechanical system fabrication, the researchers — who are based at Peking University, North China University of Technology, the Chinese Academy of Medical Sciences, and Peking University Third Hospital — can manufacture them in large arrays on a four-inch silicon wafer. These can then be separately detached and placed on different substrates, such as a flexible printed circuit board, to achieve the desired sensor distribution and density.

Original reference: Sci. Adv. 10, eadp6094 (2024)