A portable, membrane-less photocatalytic fuel cell that draws power from sunlight and uses carbon cloth electrodes costing just between ₹60 to ₹70 was developed by researchers at the MEMS, Microfluidics and Nanoelectronics (MMNE) Lab, BITS Pilani-Hyderabad.The innovation promises a lightweight, green-energy solution for portable devices and field-based IoT (Internet of Things) systems. The newly developed photocatalytic fuel cell (PFC) converts light directly into clean electricity using a compact 3D-printed chamber and a TiO₂(Titanium Dioxide) - coated carbon cloth photoanode, offering a simple, safe, and eco-friendly energy alternative, said principal investigator Sanket Goel, in an official release on Thursday.When exposed to sunlight or a small solar simulator, the TiO₂ generates electron-hole pairs that trigger electrochemical reactions with only a few drops of alkaline electrolyte (NaOH/KOH). The photogenerated electrons flow through an external circuit to produce power.The miniaturised 3D-printed architecture, with closely spaced electrodes, enables rapid ion transport, low internal resistance, and stable membrane-free operation. It delivers an open-circuit voltage (848 mV) and a power density (177 µW/cm²) enough to operate low-power electronics such as sensors and LEDs, enabling self-powered portable devices, he explained.The technology is ideal for wearable electronics, environmental sensors, and self-powered IoT nodes, such as air and water quality monitors and pollutant trackers, without relying on batteries. It can also support agriculture and irrigation monitoring systems by powering low-energy IoT devices directly from sunlight.The technology can directly power LEDs and is fully compatible with rapid, low-cost 3D printing, enabling mass fabrication. It operates at room temperature with no fuel storage, making it safe for field and on-body deployment, he added.Ph.D. scholar Sajith P.M., who designed and built the device, said: “Our goal is to develop a fuel-cell system that is not just effective in the lab, but also engineered for real-world conditions. It can provide a lightweight power source for rural areas, off-grid communities, and emergency applications where conventional electricity is unavailable”.Co-investigator Naveen K. Shrivastava observed: “This technology platform might not only generate clean energy in the future but also store it for reliable real-life use”. His colleagues Ponnalagu R.N. and Ankur Bhattacharjee added that it could pave the way for future networks requiring autonomous, maintenance-free energy sources in remote or widely distributed locations.Published - December 11, 2025 07:32 pm IST