Sustainable Food-based Nanotechnology for Sensing Applications

Abstract

Recent advancements in hydrogel nanocomposites have shown that they have the potential to be highly sensitive electromechanical sensors, surpassing the capabilities of traditional materials. One way to improve their conductivity is by incorporating a network of graphene into the composite, which affects the arrangement and structure of the graphene sheets. When the hydrogel is mechanically strained, the conductivity of the material changes accordingly, making it an ideal choice for sensitive applications. The objective of this research is to expand the investigation on sustainable nanocomposites by utilizing biodegradable polymers derived from algae These materials exhibit intriguing physical characteristics, such as transforming into hydrogels with soft mechanical properties when immersed in a food-grade calcium chloride solution. Interestingly, the mechanical properties of these hydrogels remain consistent regardless of the amount of filler added. However, the electrical conductivity of the hydrogel does increase with more filler. Furthermore, these hydrogels have the most significant piezoresistive response of any hydrogel recorded in literature, making them ideal for pressure sensing applications. They are also soft, which is another desirable quality for these applications. For impact sensing, the hydrogels display the lowest response on set impact energies on record, and their response time remains consistent. Overall, these results suggest that hydrogel nanocomposites made from biodegradable polymers could be a promising material for various applications. However, there are still some challenges that must be overcome during the development and testing of hydrogel polymers. One issue is determining the optimal level of swelling and water absorption that will not affect their mechanical properties. Additionally, hydrogels lack the ability to self-heal after undergoing testing, and they tend to dry out quickly. Factors such as size, dimensions, water content, and temperature can influence the drying process. On a different note, these characteristics make hydrogel polymers perfect for single-use or continuous wear for up to 8 hours. Thanks to their quick and cost-effective production, they are well-suited for single-patient use. After use, they can be disposed of without the need for sterilization, eliminating the risk of potential cross-infection that can occur with traditional sensors commonly found in hospitals.