Nickel-based Piezoresistive Sensors Obtained on Flexible Nanocellulose Substrate

Abstract

In the paper the biopolymer substrates were made from nanocellulose (NC), which is extracted from organosolvent reed cellulose using 2,2,6,6-tetramethylpiperidin-1-oxyl reagent (TEMPO). Nickel-based thin films were deposited on the surface of nanocellulose by RF magnetron sputtering. The peculiarities of surface morphology and chemical composition of inorganic material on the surface of biopolymer substrate were studied. Flexible strain sensors were obtained from nickel busbars on the surface of nanocellulose. The influence of overall sizes of nickel busbars on piezoresistive parameters of flexible sensors was established. It was determined that the maximum strain sensitivity is observed for a nickel busbar with a width of 1 mm, a thickness of 250 nm, a length of 15 mm and was 195,8⋆ 10-3 %. The magnitude of drift in time was 0,17 %/min. Obtained strain sensors were tested on mechanical strength depending on nickel busbar sizes. It was shown that the presence of nickel thin film increases the strength of strain sensors by 40%: from 13.8 MPa for pure nanocellulose to 19.5-19.6 MPa for nanocellulose with nickel thin films.