Biocompatible radio frequency epsilon-near-zero materials for wearable electronics

Epsilon-near-zero (ENZ) materials have attracted widespread attention due to their extremely low permittivity at plasma frequencies. In this work, carbon nanofibers encapsulating high-entropy alloy nanoparticles (HEA@CNFs) were prepared by electrospinning and three-dimensional (3D) printed into thin films with polydimethylsiloxane resin, achieving ENZ performance at 21 MHz when HEA@CNFs content reached 20 wt%. Theoretical calculations analyzed the mechanism of achieving radio frequency ENZ performance. When HEA was generated in CNFs, the delocalization ability of electrons around carbon atoms decreased, resulting in a decrease in carrier concentration. In addition, the non-parabolic enhancement and the increase in effective electron mass led to a decrease in plasma frequency. In addition to the ENZ response, the polydimethylsiloxane/HEA@CNFs ENZ film also exhibited biocompatibility and can be constructed into wearable electronic devices, realizing the detection of human body movements. It also has great application prospects in the fields of wearable medical devices and medical biological detection.