Bi-Metal Metamaterial Absorber for Wearable Sweat Sensing and Energy Harvesting Applications

The design and implementation of sensing and power mechanisms in microdevices for biomedical applications present significant challenges. In this context, we introduce a new three-layer bi-metallic metamaterial absorber. This absorber exhibits better performance characteristics, including broadband absorption above 90% in the optical wavelength range (300nm to 700nm) and narrow-band absorption above 99% in the infrared spectrum (700nm to 1800nm), facilitated by the integration of two distinct metals, aluminum, and copper. Comprehensive numerical and theoretical analyses have been conducted to validate the absorber's efficiency. These analyses include an examination of the electric and magnetic dipole interactions, as well as the electric and magnetic field distributions within the unit cell of the metamaterial. This metamaterial absorber emerges as a promising candidate for integration into wristband or armband health monitoring sensors using narrow-band absorption, particularly in applications involving solar energy harvesting utilizing the optical wavelength.