Bistable criterion for mechanically bistable mechanism

Based on slope-deflection equations, we theoretically derived a determinant D as a criterion, in terms of structural and material properties, to determine if the bistability can occur for micro mechanically bistable mechanisms. When D <; 0, it will display bistable phenomenon if an appropriate force is applied to push the bistable mechanism; while D >; 0, bistable phenomenon cannot occur. The proposed bistable mechanisms have been successfully fabricated with different beam length and tilted angle. Experiments were conducted to validate the theoretical study for bistability. Comparing theoretical results with experimental ones, it showed theoretical solutions agree well with experimental results.