Dissolvable hydrogels as transducers of bio-chemical signals: models and simulations

Hydrogels have a large number of applications in microelectromechanical systems (MEMS) technology as sensors and actuators. In this paper we investigate the use of responsive micro-sized hydrogels as transducers of biochemical signals. Hydrogels, crosslinked via disulfide bonds, when immersed in a solution containing a disulfide reducing agent can dissolve as the covalent cross-links are cleaved by the reducing agent and thereby indicate the presence of the cleaving agent. As a result, this phenomenon leads to the transduction of chemical signal to visual signal. The mechanism of the hydrogel dissolution process has been studied in detail and a mathematical model has been developed. From the vanishing time of the dissolvable hydrogel, a significant amount of information about the surrounding bath solution can be obtained.