Flexible pyroelectric device for scavenging thermal energy from chemical process and as self-powered temperature monitor

As one of the most important renewable and green sources, the development and utilization of waste heat have been received more and more attentions. A big part of waste heat comes from chemical process, which is ubiquitous in industry and laboratory. However, this form of waste heat is difficult to be utilized due to its low grade and easy dissipation. In this paper, we present a flexible pyroelectric device as a potential approach for effectively harvesting waste heat from chemical exothermic process. To achieve practical application, the pyroelectric device simply attaches to the outside of a beaker, in which various chemical exothermic processes happen. The output voltage (under input impedance of 100 M Ohm) and short-circuit current can be 9.1 V and 95 nA when the neutral reaction of sodium hydroxide and hydrochloric acid per amount-of-substance concentration proceeds in the beaker. The generated electricity can directly drive a liquid crystal display. Moreover, this pyroelectric device is also proved to be a self-powered temperature monitor reflecting chemical process in real time, as the calculated temperature variation of solution based on pyroelectric current well agrees with the measured one by thermometry reference. This work expands the development of pyroelectric device for harvesting chemical waste heat and opens up the potential applications on self-powered chemical process monitor.