Programmable Multifunctional Bistable Structures for Energy Transfer and Dissipation

Bistable structures exhibiting snap-through behavior are prevalent in nature, enabling rapid transitions between two stable states upon external stimuli. Considering such a process is accompanied by a dramatic energy conversion, here, a multifunctional bistable system composed of asymmetric bistable beams with programmable motion patterns is developed. Unlike symmetric bistable beams, the asymmetric bistable structures store greater strain energy while requiring lower activation force. The energy density of the system can be tuned by adjusting geometric parameters, type of material, and the number of beams incorporated. Experiments indicate that a three-beam system manufactured from polylactic acid projects a sphere-comparable in weight to the beams-to a height 35 times its diameter, representing a 41% increase in energy transfer efficiency compared to a single beam of identical geometry. Leveraging the programmability and high energy conversion density features of the system, we showcase its versatility in applications including targeted payload delivery, rapid stimuli-responsive actuation, and biomedical stents. Additionally, the capability of the system to dissipate impact energy is investigated, underscoring its potential for shock absorption.