Wireless CO2 SAW sensors with a nanoporous ZIF-8 sensing layer

Wireless surface acoustic wave gas sensors are potentially valuable for detecting leakage from pipelines or carbon sequestration wells. Metal organic framework materials are potential sensing layers, having nanopores with engineered size for adsorption and desorption of particular gases. Gas detection is due to the mass change resulting from adsorption, so the sensitivity is expected to increase with the thickness of the sensing layer. Here we explore the effect of relatively thick sensing layers, especially when the materials are mechanically soft.