New material for next-gen devices

Scientists have developed a new material that converts motion into electricity (piezoelectricity) with greater efficiency and without using toxic lead – paving the way for a new generation of devices that we use in everyday life. 

Publishing their discovery in Journal of the American Chemical Society, researchers from the universities of Oxford, Birmingham and Bristol describe a material that is both durable and sensitive to movement – opening possibilities for a wide range of innovative devices such as sensors, wearable electronics, and self-powered devices.

Based on bismuth iodide, an inorganic salt with low toxicity, the new soft, hybrid material discovered in Oxford rivals the performance of traditional lead-based ceramics but with lower toxicity and easier processing. It contains no lead compared to existing high-performance alternatives such as PZT (lead zirconate titanate), which is 60% lead; it can also be produced at room temperature rather than 1,000°C. 

Piezoelectric materials generate electric charge when pressed or bent and can also deform when an electric field is applied. They are essential to technologies ranging from precision actuators – used in products like camera autofocus and inkjet printer pumps – to energy-harvesting sensors built into wearable technology like fitness trackers, smart clothing, and car airbag systems.

'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,' explains lead author Dr Esther Hung, from the University of Oxford’s Department of Physics, who led the research. '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 global piezoelectric materials market continues to grow rapidly driven by demand in automotive, healthcare, robotics, and consumer electronics, where devices that convert motion into electricity or precise movement are essential. 

The researchers leading the study used single-crystal X-ray diffraction, taken at Diamond Light Source in Oxfordshire, and solid-state nuclear magnetic resonance (NMR), taken at the UK NMR facility, to understand the material’s behaviour at the atomic level. They found that the way that organic and inorganic parts stick together through halogen bonding can be used to change when and how the material changes its structure, as well as improving piezoelectric performance. Furthermore, the team performed in-situ X-ray diffraction measurements, capturing the precise structural deformations as electric fields were applied to the material.This understanding could also be useful for enhancing piezoelectric performance in other materials that combine organic and inorganic elements. 

Dr Benjamin Gallant from the University of Birmingham, who led the NMR study, adds: '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 research was jointly supervised by Professor Henry Snaith from the Department of Physics at the University of Oxford, Dr Harry Sansom from the University of Bristol, and Dr Dominik Kubicki  from the University of Birmingham, bringing together expertise in new materials, crystal design, and atomic-level structure characterisation.

'What makes this discovery so exciting is that we've demonstrated you don't need toxic materials to achieve excellent piezoelectric performance,' concludes Professor Snaith. 'This opens up possibilities for medical devices, wearable sensors, and flexible electronics that simply weren't feasible with lead-based materials.'

Tailoring a lead-free organic-inorganic halobismuthate for large piezoelectric effect, E Y H Hung et al, Journal of the American Chemical Society, 26 November 2025