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In this paper, a two-detector measuring system in in-air PIXE system composed of two Si(Li) detectors has been developed for simultaneous measurement of low- and high-Z elements. In order to improve detection sensitivity of the detector for low energy region, a new device which is attached at the tip of the detector has been designed. It is made of acryl and has a thin end on which a 1.5 μm-thick Mylar film is stuck. As a result, it exhibited a miraculous effect in improving detection sensitivity at low energies and it became possible to detect K X-rays of aluminium. In order to perform quantitative analysis in in-air system, we have measured detection efficiencies for the two Si(Li) detectors including the effect of X-ray absorption in air on the basis of the method that we developed. Concerning the beam energy at the target and corresponding X-ray production cross-sections, the same values as were reported in the previous paper were applicable since conditions of irradiating system were unchanged. It was confirmed that the new method allows us to quantitatively analyze all the elements heavier than aluminum and to obtain mostly the same results as those by in-vacuum PIXE for various kinds of samples. Accuracy of analysis was also confirmed by using a standard material.

In this paper, a surface acoustic wave (SAW) biosensor with gold delay area on LiNbO₃ substrate detecting DNA sequences is proposed. By well-designed device parameters of the SAW sensor, it achieves a high performance for highly sensitive detection of target DNA. In addition, an effective biological treatment method for DNA immobilization and abundant experimental verification of the sensing effect have made it a reliable device in DNA detection. The loading mass of the probe and target DNA sequences is obtained from the frequency shifts, which are big enough in this work due to an effective biological treatment. The experimental results show that the biosensor has a high sensitivity of 1.2 pg/ml/Hz and high selectivity characteristic is also verified by the few responses of other substances. In combination with wireless transceiver, we develop a wireless receiving and processing system that can directly display the detection results.

A highly sensitive surface plasmon resonance (SPR) sensor composed of a photonic crystal fiber (PCF) with the D-type structure is designed and analyzed by the full-vector finite element method (FEM). Indium tin oxide (ITO) is adopted as the plasmonic substance on account of the low cost and controllable infrared range (1500–2600 nm). By optimizing the structural parameters, the sensor shows a maximum wavelength sensitivity of 46,000 nm/RIU and average sensitivity of 13,166.67 nm/RIU for analyte refractive indexes between 1.355 and 1.385. This PCF combining a circular layout and D-type structure offers excellent sensitivity while the deposition and manufacturing complexity can be reduced. This sensor will possess an extremely expansive development space in the field of chemical analysis and environmental safety.

This paper describes a technique to detect blood cell levels based on the time-period modulation of a relaxation oscillator loaded with an Inter-Digitated Capacitor (IDC). A digital readout circuit has been proposed to measure the time-period difference between the two oscillators loaded with samples of healthy and (potentially) unhealthy blood. A prototype circuit was designed in 65-nm CMOS technology and post-layout simulations show 15.25-aF sensitivity. The total circuit occupies 2,184-$\mu$m² silicon area and consumes 216$\mu$A from a 1-V power supply.

A Complementary Metal Oxide Silicon (CMOS) optical micro-radiator vacuum sensor has been designed, tested and calibrated. The package is comprised of a micromachined radiator and a photodetector. The sensitivity improvement of the system over the conventional Pirani gauge is up to nine magnitudes depending on the operating power of the micro-radiator. To increase sensor's dynamic range, an automated power-switching system has been demonstrated for pressure sensing operated with constant photodetector output. Calibration of the system has been performed by comparison with secondary standards. Experimental results showed that the sensor's measurement range from 10^-3Pa to 10⁵Pa has been achieved as its relative error is less than 8%.

The detection of subtle strain on the human body by flexible sensors suffers from the inferior sensitivity. In general, poor sensitivity derives from the intact structural integrity of building blocks of electric material. Inspired by the rolling friction in daily life, a three-dimensional (3D) nanohybrid of gold@carbonaceous nanoballs (Au@CBs) is developed. Compared with the pure Au nanostructure, the CBs increase the defect sites of conductivity and deformation sensitivity between Au nanostructures. The Flexible Stress Sensor (FSS) based on the 3D nanohybrid of Au@CBs is fabricated, and due to the enough displacement variation of 3D nanohybrid of Au@CBs, the change of resistance could be triggered by the tiny stress. The as-prepared sensor has high sensitivity at wide working range ($\mathrm{\text{S}}=0.12$KPa${}^{-1}$, 0.1–10KPa and $\mathrm{\text{S}}=0.085$KPa${}^{-1}$, 10–100KPa) and good cyclic stability (5000 cycles). Finally, the FSS based on the 3D nanohybrid of Au@CBs is employed for the detection of subtle vibration and movement of the human body, such as pulse and joint bending, which exerts great potential as wearable electronics.