Strategies for Giant Mass Sensitivity Using Super-High-Frequency Acoustic Waves

Surface acoustic wave (SAW) devices are powerful platforms for mass sensing, chemical vapor or gas detection, and biomolecular identification. Great efforts have been made to achieve high sensitivities by using super-high-frequency SAW devices. Conventional sensing is based on mass-loading effects at the propagation (or delay line) region between two interdigitated transducers (IDTs). However, many with their small sizes, there a huge challenge that sensitivity difficult be further increased, simply because very limited areas IDTs deposit layer. Herein, we proposed novel strategy giant mass-sensitivity generated global area of device (defined as both line IDTs), which significantly enhances reduces detection limit device. Both theoretical analysis experimental results proved this new mechanism, mainly attributed efficient energy confinement IDTs’ The achieved 2590 MHz $\cdot $ mm notation="LaTeX">$^{{2}} \cdot \mu \text{g}^{-{1}}$ , about 500 times higher than obtained from only frequency 4.43 GHz. Hypersensitive humidity has demonstrated newly platform, achieving an extremely 278 kHz/%RH fast response recovery ~37 ~35 s, respectively.