In an era of precision medicine and big data, we have powerful computational technology to store/process data, but still lack tools to collect and control biosignals with compatible high throughput, high resolution and deep reach. The research goal of our lab is to build new paradigms of nanotechnology for biological and biomedical applications from macro to nano scale, by developing novel and aggressively miniaturized mechanical and optical probes to manipulate biological input and output signals.
By borrowing nanolithographic technology from the semiconductor industry, our lab creates designer biomaterials and metasurfaces with unprecedented precision and functionality. Integrating these nanoengineered 2D surfaces on a series of functional platforms (e.g., 3D structures, soft materials, active MEMS/NEMS), it will foster innovations for broad applications, in a dynamic and tunable fashion. In particular, our lab aims to bridge multidisciplinary knowledge and expertise, in order to develop next generation technologies to improve human health, with special focus on the following three thrusts.
I. Designer meta-optics for bioimaging and optical systems (Tissue/organ level)
By borrowing the nanolithographic technology, designer metasurfaces are composed of nanopatterned scatters with subwavelength dimensions, which engineer the wavefront with high spatial resolution and within subwavelength distance. They provide a rare opportunity to replace the conventional bulky optical elements, reduce optical system footprint, and reproduce the success of microelectronics following the Moore’s law.
Metasurfaces will enable more precise optical probes and ultra-compact systems in biomedical applications, such as a portable microscope for nondestructive pathology, and in vivo endomicroscopy by replacing conventional miniature ball lenses and GRIN lenses, which are difficult to fabricate/align/assemble, and have intrinsic aberrations. Moreover, this project also aims to create dynamic and tunable meta-optics for next-generation bioimaging and optical systems, by integrating static 2D metasurfaces on a series of functional platforms, including soft materials, active MEMS/NEMS, and tunable optical materials (e.g., liquid crystal), in order to achieve unprecedented functions, such as beam focusing/steering and optical zooming. The ultimate capability of dynamic and arbitrary light control in 3D space will extend this platform to broader applications, such as photostimulation in optogenetics.
II. Designer biomaterials for mechanobiolog (Cell level)
It became increasingly evident that besides the DNA-encoded information, extracellular mechanical factors play an important role in determining the biological processes, from cell behavior to organ formation. However, in contrast to the knowledge expansion on genome, there is still a major gap in our understanding of the molecular machines in the critical size ranging between molecular and cellular scale, due to the lack of technology to probe and control the biological machinery with high resolution and deep reach.
Mechanobiology has emerged at the interface of biology, physics, and engineering, which investigates the effects of mechanical forces and geometry on cell behavior and functions. We use the state-of-the-art nanofabrication techniques to create molecular architectures on microscope slides as biochips, an analogue of transistor arrays on silicon IC chips. These biochips can serve as a single-molecule breadboard to mimic the cell microenvironment, and probe the cellular mechanotransduction signaling with the ultimate resolution.
This project aims to create next-generation nanoengineered biomaterials for mechanobiology, by integrating a novel system with both spatiotemporal and single-molecule control. The goal is to simultaneously and independently control multiple properties and better mimic the in vivo environment, which is 3D, soft and dynamic.
III. Single-molecule investigation and biosensing (Molecular level)
Besides mechanobiology studies, our nanoarray platform can be used for high-throughput, parallel monitoring of single-molecule activities in real time. Meanwhile, dynamic tunable metasurfaces controlled by the surrounding medium, can be used as resonator arrays to sense the environment (e.g., binding of biomolecules), while eliminating the Ohmic loss in plasmonics.
On the one hand, conventional high-sensitivity medical detection techniques require sophisticated laboratory equipment, such as optical spectrometers or mechanical spectrum analyzer. On the other hand, point-of-care devices are miniaturized and cost-effective, but suffer low sensitivity and inaccurate quantification. In order to bridge this gap, this project aims to create a new generation of high-sensitivity and versatile miniaturized biosensing systems which are label-free and spectrometry-free, without the need of sophisticated equipment. Besides molecular sensing, the integration of metasurfaces on soft materials enable a novel platform of "photonic skin", with wide applications such as strain sensors and wearable devices.