M.aI.N Group

Based on front-side DRIE of SOI wafers, piezoresistive microcantilevers have been designed and fabricated.

Microcantilever sensors as a platform for bio & chemical application is a promising research area, and we have used these microcantilever sensors for the detection of proteins and other chemical substance(TMA etc).

Our research proved that curved-up piezoresistive microcantilever can be used as low-flow-rate fluidic sensors, meanwhile, our calibrated fluidic sensor has a detection range between 0cm/s and 20cm/s.

The stress sensors have been fabricated using MEMS technology.A 16×16 CMOS stress sensor array, which could be employed to measure in-plane stress distributions, is designed and fabricated with 1.2μm 1P1M process.

Based on four-point bending (4PB) method, we have calibrated the stress sensors and finished the design of experimental apparatus for stress measurement in biomedical applications.

To get the relation between the external forces and the measured stresses, a loading system capable of applying already-known forces to the teeth is developed using a pivot.

Both surface chemistry and architecture influence the fate and functions of the engrafted cells. Patterning biomolecules on solid surfaces and fabrication of three-dimensional (3-D) microstructures that mimic in vivo cellular microenvironments are of fundamental importance to cell biology and tissue engineering. We use soft lithography methods, micromolding and hot embossing, to produce cell culturing microstructure arrays of biodegradable poly (3-hydroxybutyrate-co-3-ftydroxyhexanoate) (PHBHHx) as a scaffold for the applications of tissue engineering. Mouse fibroblast cell lines L929 were cultured on PHBHHx microstructures with different configurations including circles, rectangles, and octagons in vitro.

High through-put single-cell electroporation is of great interest to the communities of cell biology, neuro-biology, and tissue engineering. We develop a single-cell electroporation chip using two complete metal electrodes and an in-between dielectric polymer layer with microwell arrays to locally electroporate hundreds of cells simultaneously with a voltage of 1V.

The dielectric microwell arrays create non-uniform electric fields and generate positive DEP forces to capture a single cell at the opening of each microwell. DC pulse voltage imposes a large electric field across the membranes of the captured cells and electroporates the cells. The electroporation chip uses a dielectric microwell array instead of common electrode arrays to perform large scale and arrayed cell operation. This electroporation chip achieves single-cell capturing and cell electroporation with the same device.

Cell patterning is an import way to understanding the influences of neighboring cells and surrounding extracellular matrix (ECM) on cell adhesion, proliferation, migration, and differentiation. We develop a cell trapping and patterning method using dielectric-layer-assisted negative dielectrophoresis (dn-DEP) to achieve high-density cell arrays and complicated cell patterns. This device has the advantages of simple configuration, low actuating voltage, and the capability in high-density trapping. As physiological media for cell culturing have high conductivity, the compatibility between negative DEP and high conductivity media make it appropriate in cell culturing.

Using microstructures with different sizes and shapes can change the hydrophobic properties of flat surface.

Accelerometer and magnetometer are used to track the orientation. The data of accelerometer and magnetometer is fused by rotation matrixes and Kalman filter.

Tests for static errors of roll, pitch and yaw are made. The static errors of roll, pitch and yaw are 1degrees, 2degrees and 5degrees, respectively.