With increasing emphasis on sustainability and human safety, biodegradable materials are being explored for modern sensor applications. This study investigates the effect of aging on the structural parameters of sensors made using κ-Carrageenan hydrogel, ferric oxide, and glycerol. κ-Carrageenan is a sulfated polysaccharide extracted from Furcellaria lumbricalis, a red edible seaweed. Hydrogels are flexible and stretchable polymers, with high moisture retention capacity, making them similar to biological tissue.
A testing sample was prepared using two aluminum electrodes and a one-year-aged sensor film (made using the procedure listed in [1]). Each electrode was connected to opposite sides and opposite ends of the sensor, leaving a 10 x 10 mm sensing area between them. The electrodes were then connected to a multimeter and a tension-compression bench to record the force, elongation, and resistance of the prepared sample.
In the performed study, we observed that the electrons have a clear path to travel through the material, leading to an increase in conductivity. The initial conductivity of the sample was 1.96E-4, increasing to 0.0852E-4 at rupture (9 mm elongation), with a maximum recorded force of 4.612 N. This structural change suggests that the aging process may have enhanced the mobility of charge carriers, contributing to the observed increase in conductivity. These findings highlight the need for a more stable composition to ensure the long-term reliability of the sensor.