Development of Environmentally Responsive Hydrogel Systems Over Micro- and Nanodevices Via ATRP

The incorporation of intelligent responsive hydrogel systems at the micro- and nanoscale has resulted in a wide variety of applications in the diagnostic and therapeutic field. Though conventional methods of the semiconductor industry have been successfully employed for the patterning of hydrogels in devices, methods for fabricating precise 3-D patterns of hydrogels at the micro- and nanoscale over material surfaces are limited. Herein, microcontact printing (µCP) for XY control, followed by atom transfer radical polymerization (ATRP) for Z/thickness control was applied to synthesize a controlled array of environmentally responsive hydrogels (e.g., N-isopropylacrylamide) over material surfaces. The controlled growth and the responsive behavior of the hydrogels to external stimuli were characterized using optical microscopy, fourier transform infrared (FTIR) imaging, atomic force microscopy (AFM), quartz crystal microbalance with dissipation (QCM-D) and scanning electron microscopy (SEM). Using this method, it is possible to synthesize hydrogels over various surfaces for potential applications in the biomedical field.