Building Flexible, Microscopic Sensor Nodes with 2D Materials

Most sensors in use today are of macroscopic dimensions. However, making sensors smaller than the diameter of a human hair could enable a new paradigm of sensing. For example, having sensors that are small and light enough to travel with the wind could be deployed by the millions in the atmosphere and would enable a new way of environmental monitoring. In this project, we work towards this vision by developing a microscopic sensor nodes, called synthetic cell or SynCell that can sense analytes in liquids or air. Our SynCells consist of 100-um-wide flexible polymer disks that have 3 chemical sensors and ID numbers as identifier in the form of ROM transistors. The transistor channels and sensors are made of a single atomic layer of molybdenum disulfide (MoS₂). This material is flexible and useful to build digital electronics as well as very sensitive sensors. So far, we have demonstrated good MoS₂ transistor performance and evaluated the response of the chemical sensors to analytes such as triethylamine. We also showed the ability to manipulate the SynCells by external magnetic fields. Furthermore, we developed a simple process to release the SynCells from the substrate by peeling them off with tape.