Provided herein are silk fibroin-based photothermal elements and uses thereof. The silk fibroin-based photothermal elements comprise a plurality of plasmonic nanoparticle distributed in a silk fibroin matrix, and can generate heat when the plasmonic nanoparticles are exposed to electromagnetic radiation. The silk fibroin-based photothermal elements can be adapted to be conformable and biodegradable, and can further be integrated with various electronic components, such as a thermo-electric device for conversion of heat into electricity. The invention is useful for various in vivo applications, such as photothermal therapy, controlled drug-delivery devices or wireless powering of implanted micro-devices.