FIG. 13.

Electrostimulation using fibers. (a) a snapshot of nanofiber-based biodegradable millirobot (Fibot) with SEM (bottom-right) and TEM (bottom-left) images of its core/shell structure. pH-responsive drug delivery (b) and its controlled release (c) using Fibot. (a)–(c) Reproduced with permission from Tan et al., Matter 5, 1277 (2022). Copyright 2022 Elsevier.¹⁷⁴ (d) Cross-sectional image of multi-layer fiber, capable of in situ drug release. (e) Photograph of in vivo application of fibrous suture. (f) The controlled release of Rhodamine B from the fibrous suture. Scale bar, 100 μm. (d)–(f) Reproduced with permission from Lee et al., Nanoscale 13, 18112 (2021). Copyright 2021 Royal Society of Chemistry.¹⁷⁵ (g) An optical and SEM (inset) image of silk optical fiber. (h) The implantation of the silk optical fiber in a freely moving mouse. Optically evoked action potential for (i) unit 1, and (j) unit 2, exhibiting multi-channel recording capabilities of this fiber-based device. (g)–(j) Reproduced with permission from Zhou et al., Microsyst. Nanoeng. 8, 118 (2022). Copyright 2022 Authors, licensed under a Creative Commons Attribution (CC BY) license.¹⁷⁶