Tactile sensors have been widely used in touch screens of smart phones to respond to touching force. Such force sensing, monitoring, and mapping are of great interest in smart system-driven healthcare, robotics and military applications. A variety of electronic and optical tactile sensors have been developed to approach the desirable tactile sensing imager with high spatial resolution and great flexibility. However, the major drawback of the state-of-the-art tactile sensors is low spatial resolutions due to their fundamental limitations on the sensor pixel size on the order of sub-centimeter/millimeter. In this work, the investigators will leverage recent advances in quantum-inspired photonics to develop a high spatial resolution tactile sensing system with highly scalable sensor pixels that can monitor strain response at a microscale. Its integration with smart phones can create a compact and portable tactile sensor platform overcoming barriers in low spatial resolution, high cost, and high instrumental complexity of the state-of-the-art tactile sensors. This research is closely integrated with the existing educational activities, providing both undergraduate and graduate students with the opportunity to participate in cutting-edge science and technology in an innovative way. The investigators also provide educational outreach activities to promote the interests and participations of K-12 students and broaden the participations from underrepresented groups.
The primary focus of this research project is to develop novel planar optical systems with optical exceptional points and arrange them on a flexible plastic platform in a chessboard configuration for high spatial resolution tactile sensing and imaging. The optical exceptional point structures, due to their planar nature, can support highly scalable fabrication using the widely used photolithography technique with spatial resolution down to even the microscale in a large area. Based upon a flexible plastic platform, this microscale tactile sensing imager can not only perform high-throughput real-time microscopic strain detection, but also enable simultaneous strain and temperature measurement with a microscopic resolution. The tactile sensor platform can be further integrated with portable electronic devices (e.g. hand-held smart phones), which would create a compact and portable tactile sensor imager platform for real-time detection in microbiology and healthcare, for example, the detection of mechanical properties of biomolecules. The principal investigators have highly complementary expertise in optics theory, advanced micro/nanofabrication technology, and device integration to design and fabricate the unique portable high spatial resolution tactile sensing platform based on novel optical exceptional point structures. The realized tactile sensing systems are expected to represent an important technological breakthrough in strain sensing, mapping and monitoring at a microscale with sensitivities orders of magnitude better than the state-of-the-art tactile sensors.
