Electronic products enhance our lives and bring change in almost every field including communications, entertainment, and healthcare. However, the fast-growing surplus of electronic waste has become a serious challenge to the environment: the majority of these toxic materials are deposited directly into landfills or incinerated because recycling is difficult and/or expensive. Electronic devices manufactured with biocompatible and biodegradable polymers are in demand because they are environmentally safe, of low cost, of potentially large volume, and are disposable. In addition, biocompatible and biodegradable electronics may enable the use of electronic devices in implantable biomedical applications. This review is focused on polymer materials, both natural and synthetic, that are utilized in biodegradable and/or biocompatible electronic devices as substrates, dielectrics, conductors, or semiconductors. Specific application examples are highlighted, such as biodegradable electronic devices, implantable medical devices, and edible sensors.

This work synergistically integrates photovoltaic and hydrovoltaic technologies, simultaneously boosting photovoltaic efficiency and hydrovoltaic output by reclaiming waste heat, providing a blueprint for self-powered energy systems.

Miniaturized pixel sizes in near-eye digital displays lead to pixel emission patterns with large divergence angles, necessitating efficient beam collimation solutions to improve the light coupling efficiency. Traditional beam collimation optics, such as lenses and cavities, are wavelength-sensitive and cannot simultaneously collimate red (R), green (G), and blue (B) light. In this work, we employed inverse design optimization and finite-difference time-domain (FDTD) simulation techniques to design a collimator comprised of nano-sized photonic structures. To alleviate the challenges of the spatial incoherence nature of micro-LED emission light, we developed a strategy called dual-task optimization. Specifically, the method models light collimation as a dual task of color routing. By optimizing a color router, which routes incident light within a small angular range to different locations based on its spectrum, we simultaneously obtained a beam collimator, which can restrict the output of the light emitted from the routing destination with a small divergence angle. We further evaluated the collimation performance for spatially incoherent RGB micro-LED light in an FDTD using a multiple-dipole simulation method, and the simulation results demonstrate that our designed collimator can increase the light coupling efficiency from approximately 30% to 60% within a divergence angle of ±20° for all R/G/B light under the spatially incoherent emission.