Unleashing elastic energy: dynamics of energy release in rubber bands and impulsive biological systems

Presenter: 

Mark Ilton

Authors: 

Mark Ilton, Suzanne Cox, Thijs Egelmeers, Sheila Patek, Alfred J. Crosby

Author Affiliation: 

University of Massachusetts Amherst, Duke University

Abstract: 

Impulsive biological systems - which include mantis shrimp, trap-jaw ants, and venus fly traps _ can reach high speeds by using elastic elements to store and rapidly release energy. The material behavior and shape changes critical to achieving rapid energy release in these systems are largely unknown due to limitations of materials testing instruments operating at high speed and large displacement. In this work, we perform fundamental, proof-of-concept measurements on the tensile retraction of elastomers. Using high speed imaging, the kinematics of retraction are measured for elastomers with varying mechanical properties and geometry. We determine empirical scaling laws which relate the observed kinematics to the underlying material properties and geometry. Understanding these scaling relations along with the material failure limits of the elastomer allows the prediction of material properties required for optimal performance. This model system provides a foundation for future work connecting continuum performance to molecular architecture in impulsive systems.