Wearable power management system enables uninterrupted battery-free data-intensive sensing and transmission

Wearable devices could provide unparalleled human-machine interaction, but their reliable powering has become a bottleneck in their widespread adoption due to requirements for uninterrupted data-intensive sensing and transmission. The current battery-free solutions cannot function with a minuscule voltage and are unable to cope with an unstable power supply. Here, we report an uninterrupted, data-intensive, and battery-free wearable multi-source power management system. The system can be charged with an intermittent ultra-low voltage (<60 mV), supporting DC and AC power from green energy sources. First, we demonstrate that by using body heat at a temperature difference of 3 K between the human skin and the environment, the system can reliably function transmitting data within a period as short as 2.25 s. Then, we show that ultra-low voltage energy harvesting driven by human motion can also power the system. The proposed power management system enables reliable battery-free uninterrupted monitoring for self-contained wearable devices.