Figure 2. Out-of-focus laser ablation generates distinct microwell shapes.

Control over z-axial distance from the laser focal plane to the PDMS surface allows fabrication of microwells with distinct shapes. (a) Example z-axial distances, shown in the schematic diagram (left), generate microwells of various dimensions including cylinders (top row), sharp cones (middle row) and rounded cones (bottom row). Cross-sectional view of PDMS (left column), confocal microscopy of volume filling fluorescent dextran (middle column), and scanning electron microscopy of polyurethane negative casts (right column). (b) Custom control over laser ablation at each point allows for mixed, interleaved microwell shapes. Cross-sectional view (left); SEM (right). All scalebars=500 μm.