November_December_2021_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 2 1 1 1 STRONGER CONDUCTING FIBERS A research team at the University of Tsukuba, Japan, is harnessing the strength of bagworm silk to produce a strong, flexible, conductive fiber. They’re building on recent findings that bagworm silk is superior to spi- der silk in both strength and flexibility. The research could lead to new flexible electronic devices, such as wearable electronic materials. It is also possible to create biocompatible materials that can be used in regenerative medicine and biomedical materials. The research team combined poly- aniline with bagworm silk obtained from a bagworm nest. The compos- ite fibers collected from the silk and Starting with natural silk from bagworms, researchers developed a strong conducting fiber that shows promise for flexible electronic materials. Courtesy of University of Tsukuba. polyaniline were 2 microns in diameter and acted as optical waveguides. They demonstrated that green laser light propagates along these fibers while remaining confined within each fiber. To determine the magnetic properties of the material, the investigators per- formed superconducting interference device measurements. The results re- vealed that the composite fibers can act as paramagnets—the fibers become magnetized when placed in an exter- nal magnetic field. The team also con- firmed the composite fiber is suitable for use in textile transistors by applying the bagworm silk and polyaniline com- posite in a field-effect transistor device. The successful production of a strong conductive fiber comprised of bagworm silk and polyaniline will pave the path toward the application of these fibers in a variety of fields such as tissue en- gineering and microelectronics. www. tsukuba.ac.jp/en.