Elastic Sheet Swimming using Dynamic Magnetic Fields

Scientific Achievement

Swimming of homogeneous 2D elastic sheets made from magnetic particles.

Upper, left:  Magnetic field H ⃑  rotating around an axis.

Upper, right:  Transverse waves propagating around the sheet with negligible sheet rotation (see black particle).

Middle:  Uncut (left) and cut (center, right) magnetic sheet causing fluid flow around the sheet, u.

Lower, left:  Swimming is induced by manipulating the sheet to control the orientation of the cut (ζS) and face (ζn).

Lower, right:  Lateral motion of sheet over time.

Significance and Impact

Understanding how to use a dynamic magnetic field and sheet symmetry to induce locomotion reduces the complexity of sheet synthesis and advances the design of autonomous, soft microrobots.

Research Details

• Above a critical rotation frequency for the magnetic field, traveling waves are produced around the magnetic sheet.

• Fluid flow caused by the motion of a sheet with broken symmetry moves the sheet along a circular path.

• A sequence of nonreciprocal sheet motion will cause swimming along a predetermined path.

• The swimming velocity can be computed by accounting for the broken sheet symmetry.

 

Locomotion of magnetoelastic membranes in viscous fluids

Brisbois, CA; Olvera de la Cruz, M
Physical Review Research, 4, 2022, 023166. 

Work performed at Northwestern University