Nonlinear Mechanics of Deformable Soft Electret Materials and the Emergent Phenomena of Pyroelectricity, Electrocaloric Effect, and the Kerr Effect



Journal Title

Journal ISSN

Volume Title



Soft materials are capable of undergoing large deformations. This is essential in several applications such as soft robotics, sensors, actuators, energy harvesting, biomimetics among other. In addition, there is a strong impetus to study \emph{multifunctional} soft materials i.e. those that show coupling between two or more fields such a deformation, electrical, magnetic, pH, temperature to name just a few. Unfortunately, most soft matters do not intrinsically possess such multifunctional couplings. In this dissertation, we outline a theoretical framework that exploits nonlinear deformation to design a soft material that exhibits an emergent pyroelectric and electrocaloric behavior. In addition, we present a nonlinear homogenization framework to design the nonlinear Kerr effect. Specifically, in this dissertation, we develop the nonlinear theory that includes the mechanical, thermal, and electrical energy of the system and address the following problems: i) Soft pyroelectric and electrocaloric materials: Pyroelectric and electrocaloric materials are restricted to hard materials or crystals. We propose the notion of using electrets and design soft composite that can \emph{behave} as pyroelectric and electrocaloric materials; ii) Pit-bearing snakes (vipers, pythons, and boas) have an extraordinary ability to ``see” and accurately locate their prey and predators in total darkness. These animals use the infrared radiation emanating from objects that are warmer relative to the background environment to form a thermal image. Building on our theoretical work on pyroeletric materials, we elucidate the central mechanism underpinning the infrared vision of snakes. Despite the exceptional simplicity of our proposed mechanism and model, we are able to explain many of central experimental results pertaining to the transduction process; iii) Soft Material and the Kerr effect: A nonlinear homogenization approach is developed to design the so-called Kerr effect in soft materials.



Pyroelectricity, Electrocaloric, Kerr Effect, Electrets, Snake, IR Detection, Pit Membrane


Portions of this document appear in: Darbaniyan, Faezeh, Kaushik Dayal, Liping Liu, and Pradeep Sharma. "Designing soft pyroelectric and electrocaloric materials using electrets." Soft matter 15, no. 2 (2019): 262-277.