Nano-biosupercapacitors enable autarkic sensor operation in blood.

Lee, Yeji; Bandari, Vineeth Kumar; Li, Zhe; Medina-Sánchez, Mariana; Maitz, Manfred F; Karnaushenko, Daniil; Tsurkan, Mikhail V; Karnaushenko, Dmitriy D et al. · Nat Commun · 2021

basic_science · Level V

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Abstract

Today's smallest energy storage devices for in-vivo applications are larger than 3 mm<sup>3</sup> and lack the ability to continuously drive the complex functions of smart dust electronic and microrobotic systems. Here, we create a tubular biosupercapacitor occupying a mere volume of 1/1000 mm<sup>3</sup> (=1 nanoliter), yet delivering up to 1.6 V in blood. The tubular geometry of this nano-biosupercapacitor provides efficient self-protection against external forces from pulsating blood or muscle contraction. Redox enzymes and living cells, naturally present in blood boost the performance of the device by 40% and help to solve the self-discharging problem persistently encountered by miniaturized supercapacitors. At full capacity, the nano-biosupercapacitors drive a complex integrated sensor system to measure the pH-value in blood. This demonstration opens up opportunities for next generation intravascular implants and microrobotic systems operating in hard-to-reach small spaces deep inside the human body.

Medical subject headings