Figure 3

High-speed imaging captures the translational and rotation motion of acousticmicroswimmers moving through either a water/microbead mixture orhydrogel.

(a), A single on-centre bubble generates linear motion in water, as does (b),a pair of bubbles of equal size symmetrically placed. An off-centreindentation generates either (c), clockwise or (d), counterclockwise motion.(e), The same rotary motion (or linear motion, not shown) can also beachieved in viscous shear-thinning hydrogel.