Piezoelectric paint-based force sensor for hand rehabilitation

A novel hand rehabilitation device for spinal cord injury patients has been designed with piezoelectric paint-based cantiléver beam force sensors. The piezoelectric paint is made of piezoelectric powder homogeneously distributed in a polymer binder (water-based acrylic). The proposed device is constituted by 16 cantilever beam force sensors activated by push-buttons which allows us to measure the applied forcé with the fingers of the hand helping in the recovery of the patient. The sensors were calibrated, obtaining a linear relationship between the electric signal and the applied forcé and a sensitivity about 8 V/N. The proposed method has been designed to improve the hand-eye coordination when the patient applies a controlled force with the fingers. Two exercises were proposed for tracking different force profiles and demonstrate the usefulnes of the device.