Figure 5.

(a) Degradation of a GelMA helical microstructure in a collagenase solution (0.1 mg mL⁻¹) (reprinted with permission from Ref. [29]). (b) Enzymatic biodegradation and magnetic retrieval of SPIONs from the GelMA microrobot in the absence of hNTSCs (reprinted with permission from Ref. [75]). (c) Transformation of the morphology of Avi/bUre microtube in pronase solution at 37 °C. (reprinted with permission from Ref. [77]). (d) Optical images displaying the degradation process of magnetoelectric (ME) soft helical microswimmers after being cultured with cells for 0, 1, 3, and 7 days (reprinted with permission from Ref. [76]). (e) Differential interference contrast (DIC) images of a degrading microswimmer array with 4 μg/mL of enzyme (reprinted with permission from Ref. [30]) (f) Microscopic observations of self-propulsion of aGD/Cat MTs through the jetting of O₂ bubbles in phosphate buffer (PB) solution and hydrolysis reaction of MTs. The red arrows indicate the direction of O₂ bubbles (reprinted with permission from Ref. [78]).