Fig. 8. Silk fibroin serves as fundamental components for implantable electronic devices.

a A silk-enabled conformal multifunctional bioelectronic device was successfully tightly integrated onto the surface of a rat brain by using a silk film as a temporary intermediate medium¹²⁹. Reproduced with permission from Wiley (2019). b A silk film-based implantable transient electronic device for wireless thermal therapy and c silk film-based controlled drug release technology were codeveloped by Omenetto et al. from Tufts University and Rogers et al. from Northwestern University^54,55. Reproduced with permission from AAAS (2012) and PNAS (2014). d A silk sponge-based implantable microneedle array for minimally invasive drug delivery was proposed by Gao et al.⁴⁹. Reproduced with permission from ACS (2019). e A functionalized silk hydrogel for bone defect repair was achieved by introducing a small peptide gelator (e.g., NapFFRGD)¹³¹. Reproduced with permission from Wiley (2018)