Commercial tactile sensors for hand exoskeletons: practical considerations for ultra-low cost and very-low complexity read-out

In the last two decades, wearable robots have emerged as human-oriented devices to complement, substitute or enhance human capabilities and, more specifically, empower or replace a human limb [1], [2]. Among the most complex and interesting limbs to assist, the hand represents perhaps the biggest challenge, because of its primary role in environment exploration, stimuli sensing and object manipulation [3]. Hence, the development of wearable and rehabilitative exoskeletons is increasingly attracting attention to help finger movements in free motion and assist the user with grasping. This paper shows that a simple underpowered digital oscillator electronic interface takes advantage of the capacitive variations in commercial piezoresistive transducers to sense applied pressure. Furthermore, thanks to the analysis of the static performance, practical considerations are drawn about the use of commercial sensors and a read out circuit (ROC) to be exploited in a control system for hand exoskeletons (Fig. 1).