Very thin nylon films were created that can be used in electronic memory components. The films are several hundreds of times thinner than a human hair and could be used in bendable electronic devices or for electronics in clothing.
Nylon synthetic polymers consist of a long chain of repeated molecular units in which each repeated unit contains a specific arrangement of hydrogen, oxygen, and nitrogen with carbon atoms.
Besides use in textiles, some nylons also exhibit ferroelectric properties — positive and negative electric charges can be separated and this state can be maintained. The ferroelectric materials are used in sensors, actuators, memories, and energy-harvesting devices.
Polymers can be liquified using adequate solvents and therefore processed from solution at low cost to form flexible thin films suitable for electronic devices such as capacitors, transistors, and diodes. This makes ferroelectric polymers a viable choice for integration with e-textiles. Although nylon polymers have found significant commercial applications in fabrics and fibers, their application in electronic devices was hindered because it was impossible to create high-quality thin films of ferroelectric nylons by solution processing.
A method to fabricate ferroelectric nylon thin-film capacitors was developed by dissolving nylon in a mixture of trifluoroacetic acid and acetone and solidifying it again in vacuum. The thin nylon films are typically only a few hundred nanometers thick. The extremely smooth thin films prevent electrical breakdown of capacitors that destroys electronic circuits. The smoothness allows for transparent thin films and transparent electronic devices.
Using this method, high-performance nylon capacitors were produced. The capacitors were subjected to extended stress cycles and demonstrated robustness of the ferroelectric nylons under millions of operation cycles. The nylon films pave the way towards multi-functional fabrics that serve as clothing that can generate electricity from body movement.