Researchers at Northwestern University have developed a new soft, sustainable electroactive material with potential applications in medical devices, wearable technology, and human-computer interfaces. The study was published in the journal Nature on October 9.
The material is made from peptides and small molecular segments found in plastics. It forms tiny, flexible nano-sized ribbons that can store energy or record digital information. These materials are highly energy-efficient, biocompatible, and sustainable. Samuel I. Stupp, who led the study, said this innovation could lead to ultralight electronic devices with reduced environmental impact.
Stupp envisions future applications such as smart fabrics or medical implants that feel like tissues and are activated wirelessly to improve heart or brain function. "This is a wholly new concept in materials science and soft materials research," he stated.
The secret behind the material lies in peptide amphiphiles—molecules previously developed in Stupp's laboratory—that self-assemble into filaments when placed in water. In this study, researchers replaced part of these molecules with a segment of polyvinylidene fluoride (PVDF), known for its electrical properties like piezoelectricity and ferroelectricity.
"PVDF was discovered in the late 1960s," Stupp explained. "It has all the robustness of plastic while being useful for electrical devices." However, its ferroelectric character is not stable at high temperatures.
The team synthesized miniature polymers from PVDF that organize into a stable ferroelectric phase using beta-sheet structures found in proteins. "The combination of two unlikely partners—peptides and plastics—led to a breakthrough," Stupp said.
These new materials can switch polarity using low external voltages, opening possibilities for low-power electronics and sustainable nanoscale devices. They could also be functionalized with bioactive signals for biomedical technologies.
"The energy required to flip their poles is the lowest ever reported for multiaxial soft ferroelectrics," noted Stupp.
In addition to their technological potential, these materials offer environmental benefits as they can biodegrade or be reused without harmful solvents or processes. Stupp mentioned exploring non-conventional applications such as biomedical devices and renewable energy catalytic processes.
The research was supported by the U.S. Department of Energy under awards DE-SC0020884 and DE-SC0000989.