Fig. 1.

Wafer-scale fabrication of arrayed chemotaxis platform. A. Standard photolithographic techniques are used to fabricate SU-8 master molds on 6″ silicon wafers, for the network (upper) and control (lower) layers, respectively. B. PDMS-curing agent mixture is spun-coated and poured to create replicas of the network (upper) and control layers (lower), respectively. C. After curing, plasma-treated PDMS layers are aligned using ethanol as a lubricant and then dried to establish contact between the layers. D. Bonded layers of forty-eight platforms are cut and plasma-treated for bonding to a glass-bottomed plate as a single piece with two control lines for large-scale applications. Scale bar, 1 cm.