Schematic illustration of the biomimetic flexible friction force sensor for dexterous neuroprosthetics. (a, b) The significance of static and sliding friction forces in daily life. The perception of slippage allows people to grasp the target objects more stably by adjusting the gripping strength without visual aid. The perception of the static friction force is closely related to estimating the weight of an object. With the perception of slippage and weight, prosthetics become “smarter” and are able to achieve some complex tasks without visual aid. (c) The bionic mechanism of neuroprosthetics to regenerate the perception of touch. For human touch, two key factors are fingerprints and four types of mechanoreceptors, which selectively respond to different types of forces. We designed a fingerprint-structured flexible capacitive sensor with custom-designed signal encoding circuit to mimic Ruffini ending functions. The output bionic pulsed signals can be transferred to the nerve tissue.