A force sensor particularly suited for use in an electronic stylus that senses the contact force on its nib for recording pen strokes and handwriting recognition. The sensor has a housing for a load bearing member for receiving an input force to be sensed and associated circuitry for converting the input force into an output signal indicative of the input force. A coupling transmits the input force to the load bearing member and, a compressible reservoir containing dilatant fluid mounted between the housing and the coupling restricts the input force to the load bearing member caused by shock loading to the coupling. This protects the force sensor from damage by sharp impact loads such as dropping the stylus on its nib.