NASA Langley Research Center has developed a method of depositing arrays of a ferritin protein on a substrate to create a thin-film electrode for a bio-nanobattery. The method is a spin self-assembly procedure by which a first ferritin layer is formed on the substrate, followed by building a second oppositely charged ferritin layer on the top of the first to form a bilayer structure. Oppositely charged ferritin layers are subsequently deposited on top of each other until a desired number of bilayer structures is produced. The result is an ordered, uniform, stable, and robust thin-film electrode material of enhanced packing density that provides optimal charge density for the bio-nanobattery.

Ferritin is an iron storage protein that naturally exists in most biological systems. The ferritin molecule consists of a segmented protein shell with an outer diameter of 12.5 nm and an inner diameter of 7.5 nm, containing up to ~4500 Fe3+ atoms as Fe(OH)3 within its hollow interior. Biomineralization allows ferritins to reconstitute themselves with various metallic cores such as cobalt and manganese.

When the ferritin half-cells are integrated into a complete battery system, the fabrication of well-organized ferritin arrays is very important to enhance the overall battery performance; for example, the battery power density, the power discharge rate, the compactness of battery size, etc.

NASA is actively seeking licensees to commercialize this technology. Please contact The Technology Gateway at This email address is being protected from spambots. You need JavaScript enabled to view it. to initiate licensing discussions. Follow this link here  for more information.


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This article first appeared in the July, 2020 issue of Tech Briefs Magazine.

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