A Nearly Packaging-Free Design Paradigm for Light, Powerful, and Energy-Dense Primary Microbatteries.

Billions of internet connected devices used for medicine, wearables, and robotics require microbattery power sources, but the conflicting scaling laws between electronics and energy storage have led to inadequate power sources that severely limit the performance of these physically small devices. Reported here is a new design paradigm for primary microbatteries that drastically improves energy and power density by eliminating the vast majority of the packaging and through the use of high-energy-density anode and cathode materials. These light (50-80 mg) and small (20-40 µL) microbatteries are enabled though the electroplating of 130 µm-thick 94% dense additive-free and crystallographically oriented LiCoO onto thin metal foils, which also act as the encapsulation layer.

Polymer grafted on carbon nanotubes as a flexible cathode for aqueous zinc ion batteries.

We have developed a free-standing, flexible cathode for an aqueous zinc ion battery by grafting cross-linked polydopamine on carbon nanotubes. The cathode is highly stable, with little capacity degradation for 500 cycles. The flexible cathode is environmentally benign and biocompatible which can enable applications from biomedical devices to grid storage.

Dendrite Suppression Membranes for Rechargeable Zinc Batteries.

Aqueous batteries with zinc metal anodes are promising alternatives to Li-ion batteries for grid storage because of their abundance and benefits in cost, safety, and nontoxicity. However, short cyclability due to zinc dendrite growth remains a major obstacle. Here, we report a cross-linked polyacrylonitrile (PAN)-based cation exchange membrane that is low cost and mechanically robust.

Mimicking Melanosomes: Polydopamine Nanoparticles as Artificial Microparasols.

A primary role of melanin in skin is the prevention of UV-induced nuclear DNA damage to human skin cells, where it serves to screen out harmful UV radiation. Melanin is delivered to keratinocytes in the skin after being excreted as melanosomes from melanocytes. Defects in melanin production in humans can cause diseases, many of which currently lack effective treatments due to their genetic origins (e.

Bio-Inspired Structural Colors Produced via Self-Assembly of Synthetic Melanin Nanoparticles.

Structural colors arising from interactions of light with submicron scale periodic structures have been found in many species across all taxa, serving multiple biological functions including sexual signaling, camouflage, and aposematism. Directly inspired by the extensive use of self-assembled melanosomes to produce colors in avian feathers, we set out to synthesize and assemble polydopamine-based synthetic melanin nanoparticles in an effort to fabricate colored films. We have quantitatively demonstrated that synthetic melanin nanoparticles have a high refractive index and broad absorption spanning across the UV-visible range, similar to natural melanins.