Solid-State Hydrogen Fuel by PSII–Chitin Composite and Application to Biofuel Cell

Biomaterials attract a lot of attention as next-generation materials. Especially in the energy field, fuel cells based on biomaterials can further develop clean next-generation energy and are focused on with great interest. In this study, solid-state hydrogen fuel (PSII–chitin composite) composed of the photosystem II (PSII) and hydrated chitin composite was successfully created. Moreover, a biofuel cell consisting of the electrolyte of chitin and the hydrogen fuel using the PSII–chitin composite was fabricated, and its characteristic feature was investigated. We found that proton conductivity in the PSII–chitin composite increases by light irradiation. This result indicates that protons generate in the PSII–chitin composite by light irradiation. It was also found that the biofuel cell using the PSII–chitin composite hydrogen fuel and the chitin electrolyte exhibits the maximum power density of 0.19 mW/cm2. In addition, this biofuel cell can drive an LED lamp. These results indicate that the solid-state biofuel cell based on the bioelectrolyte “chitin” and biofuel “the PSII–chitin composite” can be realized. This novel solid-state fuel cell will be helpful to the fabrication of next-generation energy.

Additively Manufactured Microfluidic Enzymatic Biofuel Cell with Comb -like Bioelectrodes

3D printing is a growing processing technology, which offers manufacturing of tailored, portable and integrable electrochemical energy harvesting device for realising next generation bioelectronics devices. Enzymatic biofuel cells (EBFCs) associated with biocatalysis uses biofriendly alternatives for energy harvesting. Also at microscale, the precision design and assembling of the bioelectrodes are complex procedures. The combination of computer-assisted design and 3D printing has enabled the realization of customized electrochemical miniaturized devices for various applications. In this work, a completely 3D printed EBFC at a micro level configuration, names as 3D-µEBFC, integrated with new precise bioelectrode configuration has been demonstrated. The 3D-µEBFC consists of bioelectrode with comb-like structures with carbon black which helps in increasing the active surface to volume ratio available for electrocatalysis by 80 times higher than plain electrodes. This micro-device produced an output power density of 13 µW/cm2 with an open circuit voltage of 570 mV. The 3D printed bioelectrodes show high stability, which may transform the fabrication methodology by decreasing production costs and time, letting the development of complex-shaped and purely 3D printed micro-devices.