A wearable pyroelectric nanogenerator and self-powered breathing sensor

Wasted heat is one of the most abundant and widely available energy sources in our living environment and industrial activities. Pyroelectric nanogenerators (PyNGs) is emerging as a powerful tool to scavenge wasted heat. Here we designed and fabricated a wearable PyNG using PVDF thin film integrated in a N95 respirator for scavenging energy of human respiration. Due to the temperature fluctuation induced by human breathing at 5 degrees C ambient temperature, the PyNG can generate output signals with an open-circuit voltage of 42 V and a short-circuit current of 2.5 mu A, respectively. The maximal power reached up to 8.31 mu W with an external load of 50 MO, which can be utilized to directly drive electronics, such as a liquid crystal display and light emitting diodes. This PyNG has also been demonstrated as self-powered human breathing and temperature sensors. The excellent performances and unencumbered wearable mode of the PyNG demonstrate that the device can be developed as a promising wearable energy harvester and self-powered multifunctional sensors for practical applications.