A rapid-response soft end effector inspired by the hummingbird beak

Area of Science:

• * Robotics
• * Bio-inspired Engineering
• * Nonlinear Mechanics

Background:

• * Elastic instabilities in biology enable swift movements.
• * Hummingbird beaks exhibit rapid closure via snap-through deformations.
• * Soft robots can benefit from power amplification mechanisms.

Purpose of the Study:

• * Design and test a novel, rapid-response soft end effector inspired by hummingbird beak mechanics.
• * Investigate elastic instabilities as a power-amplification mechanism for soft robots.
• * Understand the role of pre-stress fields in achieving swift, efficient robotic movement.

Main Methods:

• * Nonlinear finite element simulations coupled with continuation algorithms.
• * Analysis of the equilibrium manifold and saddle-node bifurcation.
• * Experimental testing of a thermoplastic polyurethane prototype end effector.

Main Results:

• * Identified critical intermediate rotation input for elastic energy accumulation and explosive release.
• * Numerical simulations supported by experimental results on prototype performance.
• * Demonstrated effective energy transfer to a pendulum, validating the bio-inspired design.

Conclusions:

• * Bio-inspired design effectively utilizes elastic instabilities for rapid, powerful actuation in soft robots.
• * Pre-stress fields are crucial for high input-to-output energy efficiency in soft robotic systems.
• * The developed end effector shows potential for robotic applications requiring explosive action.