Intensified microalgal biophotovoltaics using latex-based living biocomposites for enhancing electrical production

Abstract

There is a growing demand for employing Internet of Things (IoT) devices and sensors to optimize efficiency and ensure more resilient production systems. However, the widespread use of batteries to power those devices raises concerns over charges running out and environmental concerns. Hence, energy harvesting devices have emerged as a sustainable alternative by converting ambient energy sources (e.g. light, heat, or vibration) into usable power. Among these, biophotovoltaics (BPVs) utilize photosynthetic microorganisms to generate electricity, offering advantages such as environmental compatibility, self-repair, and nighttime operation, representing an ideal device for continuous low-power applications. To address the low power output of BPVs, this study introduces a novel approach using latex-based living biocomposites technology incorporating the green microalga Chlorella vulgaris TISTR 8580 immobilized on ITO-PET electrodes using an acrylic latex binder to facilitate transparent, durable film that supports photosynthesis, cell adhesiveness and mass transfer. The fabricated electrodes have been proved to generate biological current. With the developed electrodes, the BPV performance achieved a maximum power density of 0.29 W m−2, which was obtained from a 20:100 binder-to-cell volume ratio, almost five times outperforming the binder-free condition. This ratio balances a sufficient binder concentration to ensure cell retention without exceeding levels that hinder mass transport, biological activity, or introduce cytotoxicity. The integration of living biocomposites technology offers a promising improvement to conventional BPVs, intensifying device performance. and demonstrating practical sensor powering applications.