Tseng et al. employed a materials-based approach to enhance the utility of traditional dielectric sensors by creating a conformal radiofrequency (RF) construct composed of an active layer encapsulated between two reverse-facing split ring resonators. These small (as tiny as 2 mm × 2 mm) passive dielectric sensors demonstrated increased sensitivity, which could be further improved by functionalizing the interlayer material. They demonstrated in vivo use by adhering the device to tooth enamel to detect food during human ingestion. These sensors can be easily multiplexed, providing data-rich temporal information during the diffusion of analytes within the trilayer structure. This format has the potential to be extended to a variety of interlayer materials, enabling the development of sensing devices with increased utility and specificity. Lee et al. recently presented a soft, low-profile intraoral electronic device designed to continuously monitor sodium intake through long-range wireless telemetry in real-time. The stretchable, hybrid electronic system combined chip-scale components and microstructured sodium sensors with flexible interconnects, all embedded within an ultra-soft, breathable, microporous membrane.