Flexible pyroelectric generators for scavenging ambient thermal energy and as self-powered thermosensors

• A flexible PG (pyroelectric generator) based upon a PVDF (polyvinylidene fluoride) film has been fabricated.
• The PG can harvest thermal energy from the time-dependent fluctuating temperature.
• The PG can directly drive a LCD (liquid crystal display) or LEDs (light emitting diodes), or to charge a commercial capacitor.
• The PG can be used to construct a self-powered thermosensor.

Wasted heat is one of the most abundant and widely available energy sources in our living environment and industrial activities. A lot of attentions have been paid on harvesting ambient wasted thermal energy. In this work, a flexible PG (pyroelectric generator) based upon a thin PVDF (polyvinylidene fluoride) film has been fabricated. Based on the pyroelectric effect, the PG can harvest thermal energy arising from the time-dependent fluctuating temperature with spatial uniformity. At the temperature change of 50 K, the PG can deliver an open-circuit voltage of 8.2 V and a short-circuit current of 0.8 μA, respectively, with the maximal output power of 2.2 μW on a load of 0.1 MΩ, which can be utilized to directly drive a LCD (liquid crystal display) or LEDs (light emitting diodes), or to charge a commercial capacitor for subsequent usages. Moreover, the PG can be used to construct a self-powered thermosensor as a result of the linear relationship between the output voltage and the temperature change. Our study promotes the development of the PG for scavenging wasted thermal energy and opens up plenty of potential self-powered applications.