Bio-hydrovoltaic technology: advancing from non-living to living hydrovoltaic systems

Bio-hydrovoltaic systems, which leverage the energy embedded in water's natural processes, present a promising avenue for sustainable energy production. Despite notable advances in non-living hydrovoltaic systems, research into biological materials remains relatively underdeveloped, leaving their unique advantages and long-term reliability potential largely untapped. This Review presents a comprehensive synthesis of progress in the field, with a particular focus on the evolution from non-living to living hydrovoltaic systems, and a precise articulation of their conceptual boundaries. We underscore a shift from structure-oriented material engineering toward biofunction-enabled energy conversion-a transition that enables breakthroughs in power output, system durability and environmental adaptability. Through systematic comparisons of mechanisms, biomaterial sources, performance metrics and emerging application scenarios, we identify current bottlenecks and propose targeted strategies. In light of recent trends, living hydrovoltaic systems hold particular promise as a forward-looking direction, offering a transformative platform for future hydrovoltaic internet, intelligence and ecological integration at scale.