A possible obstacle for their full deployment in these markets is their energy autonomy: in order to reinforce the concept of “wearable”, small batteries are necessary and improvements should be made in energy efficiency and power management.
The integration of electronics has generated many applications and multifunctional scenarios by offering new control opportunities to improve our living environment. Technological advances are travelling at a high rate, and the possibilities offered by wearable devices embrace the field of medicine. Health monitoring wearables can allow a firm control of vital signs, all in real time, offering industry experts the possibility to access monitoring data through the cloud. The amount of information managed by a normal wearable device, the visual LED interface and the BLE communication protocol require efficient power management solutions for long-life products, but also provide new opportunities for recharging by using energy harvesting solutions. Wearables prove to be a fertile ground for the use of energy harvesting techniques, where one can exploit the kinetic energy of the wearer to produce electricity and directly recharge the battery of the worn device – see figure 1.