The response of capacitive and resistive humidity sensors based on nanocellulose was in the range of 0,61 - 21 nF and in the range of 1,3*10 ¹ - 2,1*10 ⁴ correspondingly in depend on initial raw materials, method of nanocellulose obtaining as well as weight of it on sensitive surface. The maximum value of sensitivity for both types of sensors reached up to 0,14 (%RH) ^-1 .25:T44a,The study describes methods for preparing cellulose from miscanthus stalks in an environmentally friendly way using a solution of peracetic acid and nanocellulose by the method of hydrolysis of organosolv miscanthus pulp. The properties and application of nanocellulose in capacitive and resistive humidity sensors have been studied. We have investigated influence of electrode parameters and operating frequency on sensor characteristics. It was determined that device sensitivity increases with decreasing of the distance between electrodes and operating frequency. The responses of capacitive and resistive humidity sensors based on nanocellulose were in the range of 1.15 - 102 nF and 5,1*10 ¹ - 1,1*10 ³ correspondingly. The maximum value of sensitivity was reached up to 0,094 (%RH) ⁻¹ .26:T4da,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.

Vladyslav Lapshuda

Publications