This study presents a novel chipless complementary split-ring resonator (CSRR) loaded substrate integrated waveguide (SIW) tag, coupled with an ultra-wideband coplanar antenna, for real-time monitoring of lubricant evaporation on lubricant-infused surfaces (LISs). The sensor introduces a new method for assessing the stability of the lubricant layer, a critical factor for the efficient operation of these coatings. Its design and functionality have been validated through simulations and measurements of the evaporation rate of two different lubricants with different vapor pressures, demonstrating high sensitivity in detecting lubricant evaporation. This sensor represents a significant advancement in biomaterial development and testing, providing a real-time solution to ensure the effectiveness of lubricant-infused coatings, which is essential for minimizing complications like non-specific adhesion of blood components and bacteria.

This paper introduces a novel technique based on a planar microwave sensor for contactless monitoring of hydrocarbon contamination in groundwater. Short-chain hydrocarbons are more toxic and volatile, which makes their detection vital for the management of Petroleum Hydrocarbons (PHCs) pollution in aquatic environments. The sensor consists of a tag and reader, which are wirelessly connected; hence, non-contact and highly sensitive sensing is enabled. The tag is fabricated on a flexible substrate for ease in the monitoring of the alkanes. This non-contact nature, coupled with high resolution, makes this sensor ideal for monitoring hazardous and toxic hydrocarbons in groundwater. The detection of Hexane has been studied by varying its concentration in water up to 30% (v/v).