Towards wearable autonomous microsystems, Pervasive Computing

Abstract. This paper presents our work towards a wearable autonomous microsystem for context recognition. The design process needs to take into account the properties ofa wearable environment in terms ofsensor placement for data extraction, energy harvesting, comfort and easy integration into clothes and accessories. We suggest to encapsulate the system in an embroidery or a button. The study ofa microsystem consisting ofa light sensor, a microphone, an accelerometer, a microprocessor and a RF transceiver shows that it is feasible to integrate such a system in a button-like form of 12 mm diameter and 4 mm thickness. We discuss packaging and assembly aspects ofsuch a system. Additionally, we argue that a solar cell on top ofthe button – together with a lithium polymer battery as energy storage – is capable to power the system even for a user who works predominantly indoors.