A conceptual molecular image from Adobe Stock.
Researchers at Case Western Reserve University have developed a new family of flexible, eco-friendly plastics that could be used in wearable electronics, sensors, and cooling devices. The materials are a new type of ferroelectric polymer made without fluorine, a component of environmentally persistent materials known as “forever chemicals.” The team published their findings in the journal Science.
Ferroelectric materials have a built-in electrical polarity that can be rapidly switched by applying an electric field, a property that allows for smaller, more efficient electronic components. While conventional ceramic ferroelectric materials are rigid and brittle, existing flexible polymers often come with an environmental cost. The paper notes that the most common ferroelectric polymers, based on polyvinylidene fluoride (PVDF), “are often categorized as potential ‘forever chemicals,’ raising environmental and health concerns because of their environmental persistence.”
A fluorine-free polymer template for diverse applications
To solve this, the team designed a fluorine-free polymer. By making a small chemical tweak, they created two distinct versions: one that acts as a normal ferroelectric by forming a crystal structure, and another, a “relaxor” ferroelectric, that exhibits its useful properties while in a more fluid liquid-crystal phase at room temperature.
Lei Zhu
This relaxor polymer is particularly promising. It demonstrated superior performance in electroactuation (changing shape in response to electricity) and the electrocaloric effect (changing temperature in response to electricity) at low electric fields, with performance comparable or superior to state-of-the-art PVDF-based polymers. This makes it ideal for soft, flexible applications.
The paper concludes that the polymers’ “environmentally friendly nature makes them particularly promising for diverse applications, including wearable and biocompatible actuators, thermal management devices, and next-generation flexible electronics.”
“We’re still in the development stage of synthesizing small quantities and investigating the properties,” said lead researcher Lei Zhu, a professor of macromolecular science and engineering at the Case School of Engineering, “But we’re excited about the potential to replace environmentally harmful plastics in sensors and detectors.”
PFAS are forever
Forever chemicals, also called PFAS (per- and polyfluoroalkyl substances), are endocrine-disrupting chemicals (EDCs) that can have harmful effects after prolonged exposure. They take about 1,000 years to decompose. PFAS chemicals are used in clothing, cosmetics, nonstick cookware and other household items. If enough PFAS build up, they can impact a person’s hormones.
A 2023 study by the EPA estimated that 16,500 pounds of PFAS end up in U.S. landfills every year. According to the CDC, most Americans have PFAS in their blood.
