Flexible eco-friendly multilayer film heaters

Lightweight electro-thermal flexible heaters are attracting great attention for the considerable applicative potentialities. Some causes, including cost, material availability, complex manufacturing process, absence of biodegradability/recyclability, or low heating efficiency are preventing their widespread application. Herein, an expanded graphite-based polymeric film similar to buckypaper prepared by a very simple green process is proposed as an intermediate layer of a flexible electro-thermal multilayer film heater. The multilayer is also designed to be used on human skin and with any type of food. For low applied voltages, from 3 V to 8 V, a temperature ranging between 26 and 100 degrees C can be set, reaching a heating rate of 84 degrees C/min for the maximum applied voltage. A simple simulation of the heating data can help to plan the heating for specific applications. The ease of the production steps together with the absence of pollutants during the preparation process makes the designed device useable on a large scale and for a large variety of applications where values of temperature equal to or below 130 degrees C are required.