Investigation of Mechanical Properties of a Smart Hydrogel-Based Impedimetric Bending Sensor Platform.

Smart hydrogels are promising candidates for biomedical sensing elements due to their ability to exhibit a volume change in response to a wide variety of stimuli, including specific analytes, and their potential biocompatibility. The main challenge for sensor applications lies in the development of suitable transduction mechanisms for the hydrogel's swelling state. A possibly biocompatible solution is given by an impedimetric bending transducer which can be equipped with any type of smart hydrogel and therefore serve as a sensor platform for different applications. As the hydrogel's swelling response differs for each stimulus, it is crucial to design the transducer accordingly so that the bending due to the hydrogel's volume change as well as the electric output signal can be maximized. Therefore, a study of the interdependence between sensor bending stiffness and hydrogel thickness is presented here as a basis for future sensor design. Moreover, a study of repeated bending has been conducted to evaluate the stability of the mechanical properties.