Highly Efficient Lead Free Material Converts Motion into Electricity

by Sophie Jenkins
London, UK (SPX) Nov 26, 2025
Researchers from the University of Birmingham, University of Oxford, and University of Bristol have developed a material that efficiently converts mechanical motion into electricity without the use of toxic lead. Their findings, published in the Journal of the American Chemical Society, describe a bismuth iodide based hybrid that matches the performance of conventional lead based piezoelectric ceramics but is environmentally safer and can be synthesized at room temperature.

The material uses no lead, in contrast with commercially used lead zirconate titanate which contains about 60 percent lead and requires temperatures of 1000 degrees Celsius for processing. Piezoelectric materials generate electric charge when mechanical force is applied and also deform under electric fields.

Dr Esther Hung, lead author from the University of Oxford, stated, "By fine-tuning the interactions between the organic and inorganic components, we were able to create a delicate structural instability that breaks symmetry in just the right way. This interplay between order and disorder is what gives the material its exceptional piezoelectric response. It's a different approach to piezoelectricity than in traditional materials such as lead zirconate titanate (PZT), and that's what's led to these big improvements."

The bismuth iodide hybrid demonstrates durability and sensitivity, with researchers envisioning applications in sensors, wearable devices, and self powered systems. The global piezoelectric materials market exceeds 35 billion dollars and continues to grow, driven by demand in automotive, medical, robotics, and consumer electronic sectors.

Solid-state nuclear magnetic resonance and single crystal X-ray diffraction were used at the University of Birmingham to investigate the atomic scale behavior of the hybrid. Dr Benjamin Gallant, who led the NMR study, said, "As an early career researcher, it's exciting to participate in research with the power to transform our society - almost every device we use in our daily lives contains piezoelectrics."

The project was jointly supervised by Professor Henry Snaith of Oxford, Dr Harry Sansom of Bristol, and Dr Dominik Kubicki of Birmingham. Dr Kubicki noted, "With performance comparable to commercial piezoelectrics but made from non-toxic bismuth, this discovery is a new pathway toward environmentally responsible technologies that can power sensors, medical implants, and flexible electronics of the future."

Research Report:Tailoring a lead-free organic-inorganic halobismuthate for large piezoelectric effect