Figure 4.

A polystyrene (PS) chip system fabricated by injection molding and a multipurpose holder for easy alignment. a) PS chip system with 1600 microwells and universal holder for alignment. b) Images of chip components. (i) Cell chip and transfer chip (hydrogel microarray‐on‐a‐chip) are combined with the help of holes on the cell chip and pillars on the transfer chip. (ii) A two‐layer system composed of a PDMS sheet on the PS chip was applied to the transfer chip. Rigid PS body with pillars enables the simple alignment of a hydrogel microarray on a target cell chip, and an elastic PDMS sheet facilitates complete sealing between the cell chip and transfer chip (microarray‐on‐chip). (iii, iv) Universal holder was designed to assist alignment between the assembly chip and transfer chip and imaging on the microscope at a predefined position. c) Schematic illustration of experimental procedure. (i, ii) DLP array on the assembly chip is transferred to the transfer chip with the aid of the universal holder. (iii) The hydrogel microarray‐on‐chip and cell chip are combined through a 3D alignment key composed of pillars/holes. (iv) Universal holder helps to locate the cell chip and assembly chip in a predefined position on the microscope.