Innovative micro/nano-electro-mechanical devices and systems (M/NEMS) that can fulfill the requirement of various applications are in great demands, such as high-resolution sensors, micro energy harvesters, ultrasensitive biochemical sensor and clinical microsystems, and so on. Based on the foundation and achievements on micro/nanofabrication technologies, we explored a broad of M/NEMS devices and systems, and many innovative researches have been accomplished. The main contributions are included as follows:
1) Nano-electro-mechanical systems.
With the special micro/nanofabrication techniques developed in our lab, innovative NEMS devices and systems are designed and realized, including the metasurface full-color palettes and colorimetric immunoassay sensors, the tunable metamaterial as reversible switch between mid-wave and long-wave infrared regimes, the metal-film-based 3D chiral optical antennas, and various surface enhanced Raman scattering (SERS) substrates. We innovatively developed a nanofabrication-equipment free, high-throughput, yet precisely controllable and designable nanofluidics in a close-packed nanoparticle array, i.e. the nanofluidic crystal. Its applications include ultra-high-current ionic diodes, ultra-high-efficiency power energy harvesters, and ultrasensitive biosensors.
2) Micro energy harvesters and self-powered smart systems.
Micro energy source powering the sensor nodes is one of the key issues for the success deployment of IoT. Various micro energy harvesters with different working principles are explored, including electrostatic, electromagnetic, piezoelectric, etc. In particular, several innovative triboelectric nano generators (TENGs) were demonstrated, such as the first TENGs with friction layer, the transparent TENGs, and so on. Furthermore, the self-powered smart systems are also developed, resulting in the first self-powered artificial smart skin, self-powered smart patch and ultra-sensitive pressure sensor on stretch and transparent substrate, etc.
3) Bio/clinical Microsystems.
An ultra-high throughput liquid biopsy based on a Parylene C micropore array with an ultra-high porosity was demonstrated. Compared to the previous works, our work can go up to 130 mL/min for the PBS solution and 25 mL/min for the whole blood sample. A cell electroporation chip with the annular interdigital electrodes was invented, in which cell transfection and survival rates are much higher than the reported micro-chip and large commercial electroporation instrument. In addition, the flexible thin-film microelectrodes for in vivo cell electroporation and inhibiting tumor cells in vivo were demonstrated. Besides, the developed bioMEMS and micro-nanofluidic systems techniques have enabled the integration of the self-assembled biological systems, MEMS, microfluidics and CMOS in a single chip, integrating SOC and LOC.
4) Radiation detectors.
Silicon PIN radiation detector has been applied widely in the nuclear, medical and space science. With the efforts of more than fifteen years, advanced technologies for the PIN radiation detectors are developed. Benefiting from the optimized fabrication process, an ultra-low leakage current (as low as several nA per square centimeter) of the detectors is achieved. Owing to their high sensitivity and reliability, The PIN detectors have been successfully applied on satellites and nuclear researches.
Related works have been published in Nano Letts., Adv. Mater., Adv. Func. Mater., Nano Energy, Small, Lab Chip, J. MEMS, IEEE MEMS and other top tier journals and conferences in the M/NEMS fields. The works on radiation detector have won the first prize of the Science and Technology Progress Award, the Ministry of Education in 2011.
In addition to the academic achievements reported in the published publications, more than 50 Chinese patents have been issued. The team also focus on the technology transfer to the industry. Several spin-off corporations have been established based on the technologies developed by the team.