Contents lists available at ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy A pyroelectric generator as a self-powered temperature sensor for sustainable thermal energy harvesting from waste heat and human body heat Ayesha Sultana a , Md. Mehebub Alam a , Tapas Ranjan Middya a , Dipankar Mandal a,b, ⁎ a Organic Nano-Piezoelectric Device Laboratory, Department of Physics, Jadavpur University, Kolkata 700032, India b Institute of Nano Science and Technology (INST), Phase-10, Sector-64, Mohali 160062, India HIGHLIGHTS • A pyroelectric generator as a self- powered temperature sensor has been demonstrated. • A self-sustaining pyroelectric gen- erator has been realized. • It harvests heat dissipation from human body surface. • It has the potential to use as self- powered breathing sensor. • The possibility of non-invasive human healthcare monitoring has been shown. GRAPHICAL ABSTRACT A pyroelectric generator driven by water vapour and human body heat that can serve as a self-powered tem- perature sensor is presented. ARTICLE INFO Keywords: Pyroelectricity Self-powered temperature sensor Water vapour Human body heat Pyroelectric generator Thermal energy harvesting ABSTRACT Conversion of temperature fluctuations to useable electrical energy is rendered by the pyroelectric effect. Waste of heat in our day to day environment and in industrial sector constitutes an abundant source of energy. Herein, we report a pyroelectric generator (PyG) that produces pyroelectric output up to 1.5 V and 1.5 μA. Its power density is 0.034 μW/cm 2 upon exposure to heat-cool condition for a temperature variation from 310 K to 340 K. Due to the fast response time (121 ms) of the PyG, it is expected to be use as a self-powered temperature sensor. The generated electricity could also be stored in a capacitor up to 0.8 V in three heating–cooling cycles. It has been also demonstrated that PyG is possible to drive by water vapour where energy-consuming alternating devices is not necessary. The temperature oscillation achieved by spontaneous water condensation and eva- poration from the surface of the PyG that produces open-circuit voltage of 1.6 V for a temperature variation from 303 K to 333 K. Thus the PyG driven by water vapour supports an efficient retrieval of energy from hot water vapour, which is wasted mostly. The linear increment of voltage as a function of temperature indicates PyG is also suitable to use a temperature sensor that may also work in self-powered mode. In addition, the PyG can also harvest the waste body heat, i.e., heat dissipation from human body surface and from the process of respiration. That promises an effective self-powered temperature sensor that might be useful in healthcare monitoring, safety and security sectors. https://doi.org/10.1016/j.apenergy.2018.04.003 Received 9 January 2018; Received in revised form 21 March 2018; Accepted 2 April 2018 ⁎ Corresponding author at: Organic Nano-Piezoelectric Device Laboratory, Department of Physics, Jadavpur University, Kolkata 700032, India. E-mail addresses: dipankar@phys.jdvu.ac.in, dmandal@inst.ac.in (D. Mandal). Applied Energy 221 (2018) 299–307 0306-2619/ © 2018 Published by Elsevier Ltd. T