Biohybrid Energy Storage Circuits Based on Electronically Functionalized Plant Roots.

Biohybrid systems based on plants integrate plant structures and processes into technological components targeting more sustainable solutions. Plants' biocatalytic machinery, for example, has been leveraged for the organization of electronic materials directly in the vasculature and roots of living plants, resulting in biohybrid electrochemical devices. Among other applications, energy storage devices were demonstrated where the charge storage electrodes were seamlessly integrated into the plant tissue. However, the capacitance and the voltage output of a single biohybrid supercapacitor are limited. Here, we developed biohybrid circuits based on functionalized conducting roots, extending the performance of plant based biohybrid energy storage systems. We show that root-supercapacitors can be combined in series and in parallel configuration, achieving up to 1.5 V voltage output or up to 11 mF capacitance, respectively. We further demonstrate that the supercapacitors circuit can be charged with an organic photovoltaic cell, and that the stored charge can be used to power an electrochromic display or a bioelectronic device. Furthermore, the functionalized roots degrade in composting similarly to native roots. The proof-of-concept demonstrations illustrate the potential of this technology to achieve more sustainable solutions for powering low consumption devices such as bioelectronics for agriculture or IoT applications.