We proposed a multi-frequency sandwich type vibration energy harvester to widen the effective frequency range of vibration energy harvester. The harvester is composed of three resonant structures with different natural frequencies. The resonant structures are two cantilevers each with bi-layer coils and a plane spring with a magnet. The maximum peak-peak voltages of the three different frequencies are 172 mV, 104 mV and 112 mV at the frequencies of 235 Hz, 330 Hz and 430 Hz, respectively. The first maximum voltage is much higher than the others, because the coils in both cantilevers can produce voltages.

tThis article introduces a novel type of MEMS probe card that uses polymer (polydimethylsiloxane, PDMS)as an elastic layer. The elastic layer provides the flexibility when the probes are in contact with the chippads. Through-holes in the PDMS and the low temperature co-fired ceramic (LTCC) substrate lead thesignals or power to the back side of the LTCC substrate. The proposed MEMS probe card configurationpotentially improves the probe density and simplifies the fabrication process. The probes are formedby electroplating on the PDMS substrate. The PDMS elastic substrate probe card with a probe pitch of100 m was developed for area array pad testing. The contact force is approximately 18 mN when theprobes overdrive is 20 m. Coplanar waveguides structures can be fabricated on the PDMS surface. Themeasured insertion loss is 0.2 dB at 3 GHz.The test data exhibited that the PDMS elastic substrate probecard is suitable for high-frequency wafer level IC testing.

Blood analysis plays a major role in medical and science applications and white blood cells (WBCs) are most often the target of analysis. We proposed an integrated microfluidic chip for rapid trapping WBCs from whole blood directly. The microfluidic chip consists of two basic functional units: a winding channel to mix and arrays of two-layer trapping structures to trap WBCs. Red blood cells (RBCs) were eliminated through moving the winding channel and then WBCs were trapped using the arrays of trapping structures. The microfluidic chip was fabricated in the biologically compatible PDMS (polydimethylsiloxane) using MEMS (microelectromechanical system) fabrication technology. We determined the critical flow velocities of tartrazine water and brilliant blue water mixing and whole blood and red blood cell lysis buffer mixing in the winding channel. They are 0.25 μl/min and 0.05 μl/min, respectively. The critical flow velocity of the whole blood and red blood cell lysis buffer is lower due to larger volume of the RBCs and higher kinematic viscosity of the whole blood. Under this flow velocity, the RBCs were lysed completely by mixing and the WBCs were trapped by the trapping structures.

Circulating tumor cells (CTCs) from peripheral blood are emerging as a useful tool for the detection of malignancy, monitoring disease progression, and measuring response to therapy. We describe a unique microfluidic chip that was capable of efficient and selective separation of CTCs from peripheral whole blood samples. The ability of microfluidic chip to capture CTCs from PBS and whole blood samples was tested.Sixty-eight peripheral blood samples from 68 colorectal cancer patients were investigated for the presence of CTCs by microchip technology. The frequency of CTCs was analyzed statistically for correlation with relevant clinical data. We also examined samples from 20 healthy individuals as controls. The calculated capture efficiency was 85.7% and decreased significantly at flow rates above 2.0 ml/h. The number of CTCs isolated ranged from 3 to 236/ml for colorectal patients [99 ± 64 (mean ± SD) CTCs/ml]. None of the 20 healthy subjects had any identifiable CTCs. We identified CTCs in 46 (67.65%) of the 68 patients: in two of nine (22.22%) Dukes A, in 10 of 24 (41.67%) Dukes B, in 21 of 22 (95.45%) Dukes C, and in all 13 Dukes D patients. The detection rate in Dukes C and D patients was much higher than in Dukes A and B patients (97.73% vs. 36.36%) (p < 0.01). A significant correlation between detection of CTCs and clinical stage (r = 0.792, p < 0.01) was found, which was higher than carcinoembryonic antigen (r = 0.285, p > 0.01), carbohydrate antigen 19-9 (r = 0.258, p > 0.01), α-fetoprotein (r = 0.096, p > 0.01), and cancer antigen 125 (r = 0.134, p > 0.01). Microfluidic chip provides a novel method for capturing CTCs. The presence of CTCs correlated with clinical stage. It is important to evaluate CK-positive and DAPI-stained tumor cells together to determine the role of CTCs in tumor behavior and disease progression.

Electroencephalogram (EEG) has been one of the important means to study brain functions and diseases.We fabricated an innovative MEMS elastic-based dry electrode using photolithography and electroforming process.The pitch of elastic-based dry electrode tip is 100 lm.We adopted polydimethylsiloxane as an elastic layer which provides the flexibility when the conductive layer and the electrode tip contact with the skin. This kind of dry electrode array does not need conductive gel during testing procedure. Compared with the traditional Ag/AgCl wet electrode, it greatly reduced the preparation time for EEG measurement and it could make the examinee more comfortable.