Progress in stimuli-responsive hydrogel composites for digital technologies

The global demand for data storage and information security has risen to frightening levels. This is due to the global population's paradigm shift toward digital technologies. Over the years, many materials have been explored with significant success and efficiency to drive a digital economy, however, research on stimuli-responsive materials (typically hydrogels) has been an interesting innovation in modern materials science and polymer chemistry. These developed materials are declared smart owing to their unique property and mode of design which incorporates stimuli-responsive moieties into the material structure. The external stimuli that alter the properties of the developed materials sensitive to them are largely grouped into the physical stimuli (e.g., magnetic field, light, temperature, mechanical stress, electrical field) and the chemical (e.g., pH, chemical reactions, ionic strength) stimuli. Thus, the review presents studies on stimuli-responsive hydrogel composite materials with an overview of their functional characteristics, reactions to various environmental stimuli, environmental implications, and potential uses in digital technologies. The scientific breakthrough in the production of stimuli-responsive hydrogel composites is an eye-opener for the development of novel material for improved data security, data authenticity, anti-counterfeiting devices, etc.