Search

Metalenses built up by artificial sub-wavelength nanostructures have shown the capability of realizing light focusing with miniature lens size. To date, most of the reported metalenses were patterned using electron beam lithography (EBL), which requires long processing time and is not suitable for mass production. Here, we demonstrate an amorphous silicon (a-Si) metalens on a 12-inch glass wafer via the 193 nm ArF deep UV immersion lithography, with critical dimension (CD) as small as 100 nm. The layer transfer technology is developed to solve the glass wafer handling issue in complementary metal-oxide-semiconductor (CMOS) fabrication line. The measured numerical aperture (NA) is 0.494 with a beam spot size of 1.26 {\mu}m, which agrees well with the simulation results. The focusing efficiency of 29.2% is observed at the designed wavelength of 940 nm. In addition, the metalens is applied in an imaging system, which further verifies its focusing functionality.

A novel CMUT based micro viscosity sensor is presented, in which the pulse-echo ultrasound signal generated by CMUT is used as information carrier. The mechanical performance of CMUT will be changed by the viscosity of surrounding fluid medium due to the damping effect, therefore also affecting the generated ultrasound signal under the same driven condition. Through detecting this pulse-echo signal in time domain followed by performing Fourier transform, the frequency response of CMUT as well as the desired viscosity information has been successfully obtained.

We present the first energy harvester-based battery for use in sensor systems as a direct drop-in solution. The device is packaged in a standard CR2477 form factor, consisting of a vibration-based Aluminum nitride energy harvester and a power management IC (PMIC). This battery functions like a regular button cell and is able to charge up when the environmental vibration is as low as 0.85g and as high as 10.17g, with a steady DC voltage of 3.8V, which can be programmed in the PMIC. Charging up the battery requires about 16s @ 1.19g before a steady DC current is produced.

Tactile sensors for measuring elastic properties of soft tissues have been previously implemented using large piezoelectric elements. However, due to limited sensitivity and spatial resolution inherent to the large form factor, their applications are limited. In this work, we report a miniaturized ring-shaped resonant tactile sensor for material elasticity measurement. The sensor, which is based on a silicon ring resonator incorporated with a rounded sensing tip and a mechanical stopper, is able to recognize materials of different young's modulus in the GPa range.