Transfer of Energy and Momentum between Magnetoactive Surface Microstructure and a Solid Object

TL;DR

This study explores how magnetoactive surface microstructures can transfer energy and momentum to move solid objects, demonstrating rapid lamella reorientation and quantifying energy transfer limits for efficient transport.

Contribution

It introduces a detailed analysis of energy and momentum transfer mechanisms in magnetoactive elastomer microstructures under magnetic fields, highlighting new transport regimes and limits.

Findings

Lamellas reorient within milliseconds at high angular velocities.

Single lamella can transfer about 50 nJ of energy to propel objects.

Identifies three distinct transport regimes: kicking, pushing, bouncing.

Abstract

We investigated the physical mechanisms driving directional transport of solid objects by micro-lamellar structures laser-inscribed on the surface of a magnetoactive elastomer (MAE). When subjected to a rotating magnetic field with magnitude of 175 mT and a time period of 0.4 s, the lamellas reorient within a few milliseconds, reaching angular velocities up to 1100 rad/s. This rapid motion is crucial for efficient momentum and energy transfer to objects in contact with the lamellas. The analysis of collisions of a single lamella with a lead ball with a 2.2 mm diameter shows that the lamella can transfer around 50 nJ of energy, propelling the ball to a speed of around 35 mm/s. We show how this value sets the upper limit for the transport speed of the ball on multi-lamellar MAE arrays. We also explain the background of three distinct transport regimes (kicking, pushing, and bouncing modes) observed on these magnetically driven conveyor belts.