Optical bio-chemical sensors for COVID-19 detection and beyond
Photonic biosensors that use optical resonances to amplify biological signals associated with the adsorption of low-index biological markers offer high-sensitivity detection capability, real-time readout, and scalable low-cost fabrication. However, they lack inherent target specificity and can be sensitive to temperature variations and other noise sources. We introduced a concept of the High Contrast Probe Cleavage Detection (HCPCD) mechanism, which makes use of the dramatic optical signal amplification caused by cleavage of large numbers of high-contrast nanoparticle labels instead of the adsorption of low-index biological molecules. Detection specificity for and signal amplification can be achieved through the use of collateral nucleic acid cleavage caused by enzymes such as CAS12a and CAS13 after binding to a target DNA/RNA sequence.
Sustainable & easy-care fabrics for passive thermoregulation
Conventional fabrics absorb body heat and perspiration, providing fertile ground for bacterial growth. Textile production pollutes water with dangerous toxins, and 73% of fabrics end up in landfills. This project is developing a lightweight, recyclable, and stain-resistant SmartPE polyethylene textile, which passively regulates body temperature via control of radiation, thermal conduction, and evaporation, inhibits bacterial growth, saves energy and water during fabrication and usage, and can help to reduce and re-use plastic waste.
Flexoelectric photo-detectors & round-the-clock energy generators
We achieved photo-detection and energy generation in narrow-bandgap Bi2Te3 semiconductor thin films subjected to inhomogeneous strain in the absence of semiconductor junction, and without external bias. Our photo-detectors can generate electric power during both the daytime and the nighttime, by either harnessing solar and thermal radiation or by emitting thermal radiation into the cold sky, including the possibility of energy harvesting from the coldness of the universe. To the best of our knowledge, this is the first demonstration of the power generation in a simple junction-free device under negative illumination, which exhibits higher voltage than the previously used expensive commercial HgCdTe photo-diode. The technology is not limited to Bi2Te3 as the active material, and – with further material improvements – offers many potential applications in night vision, wearable sensors, long-range LIDAR, and daytime/nighttime energy generation.