Microfluidic flow assembly system with magnetic clamp for unlimited geometry in millimetric hydrogel film patterning

Polymeric sheets with geometrically selective patterns and functions can be used for many labeling and sensing applications. Conventional fabrication techniques such as templated-based printing require cumbersome, multiple and intensive steps, pose difficulty towards automation, and thus are mostly applied for simple array patterned sheets. Alternative microfluidics-based methods, such as flow lithography is limited to creating parallel patterns. We develop a microfluidic assembly fabrication based on flow lithography to make millimetric polymeric sheets with geometrically complex and selective patterns. This new fabrication is empowered by integrating a magnetically actuated clamp in the microfluidic channel. The integration of this magnetic clamp in combination of flow lithography allows rapid flow-assisted exchanges of multiple compositions during sequence patterning. Resolution is limited only by the quality of the UV photolithography source and the microscope optics. Using our method, we demonstrate the synthesis of enclosed geometrically complex hydrogels film with the inclusion of choice chemical functionalizations for pH and temperature sensing, fluorescent markers and for biomolecule sensing, fluorescence and enzymatic activity.