Investigation of the influence of the spatial structure of film strain-sensitive sensors on electromechanical properties
Anastasia S. Morozova1, Ekaterina A. Demirskaya1, Alexander Yu. Gerasimenko1,2;
1National Research University of Electronic Technology, Moscow, Zelenograd, Russia; 2.I.M. Sechenov First Moscow State Medical University, Moscow, Russia
Abstract
The paper presents a study of the electrical, mechanical and functional properties of strain-sensitive sensors based on carbon films with a laser-modified spatial structure. Carbon films were obtained by layer-by-layer spraying of dispersed media containing multi-walled carbon nanotubes and reduced graphene oxide onto elastic polydimethylsiloxane (PDMS) substrates. To solve the problem of dispersibility of carbon nanoparticles, surfactants were added to the composition of dispersed media: sodium cholate and sodium deoxycholate, as well as ethanol in volume fractions of 20% and 25%. The stability and homogeneity of dispersed media were assessed using optical spectroscopy and dynamic light scattering, and the optimal composition of the dispersion was identified. The structure of the films deposited on the PDMS was studied using scanning electron microscopy. Sensor architectures in the form of topologies have been developed for the formation of strain-sensitive sensors based on the obtained carbon films. The finite element method has been used to model sensor architectures, and the distribution of mechanical stresses in such films has been studied. As a result, two types of architectures were identified: concentrating mechanical stresses (type-C) and distributing stresses (type D). The sensor architectures were formed on carbon films by laser lithography with the following parameters: wavelength 1064 nm, beam diameter 35 microns, average radiation power 0.887 W, beam velocity 240 mm/s. A study of the electrical characteristics of films by the Van der Pau method showed that the formation of a type C architecture does not lead to significant changes in resistance, while the formation of a type D architecture increases the resistance of films by an average of 2 times. It was also found that sensors with a C-type architecture had a sensitivity to deformations 4 times greater than sensors in the form of continuous films, as well as a resistance hysteresis measured during cyclic deformation, 2 times less. At the same time, the formation of the D-type architecture led to a 3-fold decrease in hysteresis, but no significant change in the sensitivity coefficient was observed.
The work was supported by the Ministry of Education and Science of the Russian Federation (project FSMR-2024-0003).
Speaker
Anastasia S. Morozova
National Research University of Electronic Technology, Moscow, Zelenograd, Russia
Russia
Discussion
Ask question
