Journal of Bionic Engineering (2023) 20:47–56  https://doi.org/10.1007/s42235-022-00243-8 

Fabrication of Biomimetic Transparent and Flexible Pectin/PEG Composite Film for Temperature Sensing Applications 

M. E. Harikumar1  · Sudip K. Batabyal2,3 

1 Department of Electronics and Communication Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India
2 Department of Science, Amrita School of Physical Sciences, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India
3 Amrita Center for Industrial Research & Innovation (ACIRI), Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India

Abstract  In the feld of robotics to enhance the interaction with humans in real-time and in the bioengineering feld to develop prosthetic devices, the need for artifcial skin is in high demand. In this work, the hydrogen-bonded complex network structure of the Pectin/PEG composite has been designed, resulting in the free-standing flm functioning as a temperature-sensing device. With the gelation technique and the addition of PEG, the flm’s fexibility and conductivity were enhanced. The fabricated device worked at a low voltage of 1 V supply with high throughput. With diferent dimensions, three devices were fabricated, and the maximum-induced ionic current was 34 ?A±5%. The device has an average sensitivity of 1.3–2.7 ?A/°C over the range of 30 °C to 42 °C. The device's fastest response time to sense the temperature change was 2 s±5%. The present device exhibits good stability for a long duration of time. These pectin/PEG flms can be used as biomimetic skin to improve the efciency in sensing the temperature. 

Keywords  Pectin flm · Temperature sensor · Ionic current · Thermo-reversible · Thin-flm · NTC

Fig. 1 Scheme of fabrication (a), real image of the flm and fabricated device (b, and c), experimental setup (d), and fexibility testing of the flm (e)