17.10 A 0.4V, 750nW, Individually Accessible Wireless Capacitive Sensor Interface IC for a Tactile Sensing Network

Capacitive sensors are prevalent in IoT and healthcare devices due to their low cost and zero static power consumption. As a pivotal component in these devices, the sensor interface [1–4] poses distinct design challenges, especially in wireless systems with considerable channel loss. In this work, an interface IC is implemented for one such application, where it is combined with a force sensor to create a subcutaneous implant for tactile sensing. Through a sensor-brain interface, this device aims to help restore somatosensation, an important yet lacking function in the existing reanimation treatment of hand paralysis [4]. As illustrated in Fig. 17.10.1, the sensor device, intended for palm implantation, is controlled via a bidirectional inductive link with the primary coil worn on the wrist or affixed to the back of the hand, causing no interference with natural hand movements.