A Flexible RF Energy Harvester for Smart Bandages

A low-profile, lightweight, and flexible RF energy harvester operating at the UHF band for smart bandages is presented. The RF harvester consists of an all-fabric dipole antenna, a rectifier, and a Power Management Integrated Circuit (PMIC) based on the ultra-low power boost converter BQ25570. The antenna is made of Litz wire, which is couched onto a fabric bandage and resonates at 915 MHz in the presence of the body. The antenna is coupled with a coplanar waveguide (CPW) rectifier (rectenna) for RF energy harvesting. The results show that it took 50 s to turn on the boost converter when the receiving antenna is placed 1.5 m away from the transmitting antenna, indicating that the proposed harvester is suitable for powering low-power electronics over a short range for remote health care applications.