Fig. 2: Proposed microgripper with freeform geometries and misalignment of rotary microgrippers.

a Schematic view of the proposed microgripper with freeform geometries showing an arm tip, gripper arm, rotary comb actuator, connecting beam (freeform geometries), and anchor. The moving direction of the microgripper is along the direction of blue arrows. b With the use of Bezier curves, any beam can be defined with coordinates of six points. An orthogonal beam can be modified into a curved beam easily by just modifying the coordinates of P1 and P4. c Movement of a rotary comb actuator after actuation. The red line is the position of the moving comb before actuation, while the solid blue part is the position of the moving comb after actuation. The R-axis is along the radial axis of rotary comb fingers, which is the undesired displacement of comb fingers. The θ-axis is along the tangent direction of rotary comb fingers (perpendicular to the R-axis), which is the desired movement direction of comb fingers. The undesired movement along the radial axis, i.e., R_m, reduces the gap between the fixed and moving comb fingers