Fig. 2: Analysis of arm deflection in triangular finger comb drives.

a comparison of the moving arm in its undeflected and deflected states, delineating the arm’s movement due to applied restoring force and showing the reduction in the gap (\(c\) to \(c^{\prime}\) to \(c^{{\prime} {\prime}}\)). The red line represents the arm’s deflected state, with β denoting the deflection angle, and \(d^{\prime}\) indicating the reduced electrode gap due to bending. b Schematic of force application on the arm, with \({P}_{i}\) indicating the point force applied by the \({i}^{{th}}\) finger at distance \({b}_{i}\) from the anchor point, resulting in the deflected profile (red dashed line). c This graph shows the linear correlation between the maximum deflection (\({D}_{\max }\)) in nanometers and the Travel Range Sacrifice Ratio (TRSR) in percentage. As \({D}_{\max }\) increases, TRSR also increases, depicting the trade-off between actuator deflection and travel range reduction. d Required arm width vs. maximum permissible deflection (\({D}_{\max }\)) for arm length of 150 µm. The red line marks the chosen \({D}_{\max }\) of 60 nm, corresponding to a TRSR of 7%, balancing compactness and travel range. e Graph plotting the relationship between arm width (\({d}_{0}\)) and arm length (\({L}_{{arm}}\)), with various curves representing different maximum permissible deflections (\({D}_{\max }\)). f The modified arm design, depicted with a chamfered profile that mitigates stress concentration and increases the stiffness of the arm, is a strategic modification for fabrication considerations. This design adjustment specifically addresses manufacturing challenges associated with sharp corners and enhances the overall mechanical stability of the structure