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Laser Optical Tweezers
No full textThis paper describes a laser optical tweezers (LOT) system, which was constructed by combining a diode laser with an optical microscope equipped with a long working distance objective lens. The system incorporates motor-driven beam steering optics which allows for positioning the trapping spot with micrometer resolution. The LOT system was applied to the manipulation of several particles, such as a polystyrene particle, a ceramic particle, a yeast cell. etc. The optical trapping forces and the optical rotation torque of the system were determined by the viscous drag forces and torque calculated using Stokes\u27 law. The experimental results showed that trapping forces linearly increased with the laser power, and the forces generated were of the order of piconewtons (pN) when the laser power was about 10 mW. The rotation torque also linearly increased with the laser power and the observed increase in torque with power was approximately 10-19 Nm per mW. The values of the trapping forces and torque were compared to the momentum and angular momentum of the laser beam. It was shown that the LOT system developed here can be used in the manipulation of red blood cells and the rotation of a micro gear of 1μg in weight.半導体レーザと長作動距離対物レンズの組み合わせからなる光ピンセットを開発し,その基礎特性を調べた.開発した光ピンセットは各種微粒子の捕捉,移動,回転ができることを確認した.トラップ力および回転トルクはレーザパワーに比例して増加し,レーザ出力10mWでトラップ力はpN,回転トルクはpN・mmオーダとなる.フォトンの運動量および角運動量と比較した結果,トラップ力はレーザの放射圧の約2.3%,回転トルクは円偏光レーザの全トルクの約25%に相当することがわかった
The moderating effects of business strategy and organizational climate on relationship between Human Resource Management and firm performance
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Developments of Sugar Chain Modified Nano-carbon Field Effect Transistors for the Influenza Bio Sensor
No full textNano-carbon materials have highly potential for advanced devices because of the many superior properties such as high mobility, high strength and so forth. For nano devices, we can easily fabricate field effect transistors (FETs) with nano-carbon channels. Using FETs, high performance sensors, noise enhanced nonlinear devices has been developed. We have developed several processes to fabricate the field effect transistors for the bio-sensor. One is the self-alignment process using grapho-epitaxy for the nano-carbon channels. Second is the deposition process for the binding molecules for the specific molecules such as avian influenza viruses and human-type ones. In this paper, we have deposited carbon materials by chemical vapor deposition and fabricated FETs using self-alignment process. We discuss about the deposition temperature dependence using the Raman spectroscopy and the measurements of electronic properties such as the drain-source current (IDS). The grapho-epitaxy can enhance the graphene layers growth and also induce the defects caused by the strain in the carbon nanowalls (CNWs). The scattering at the grain boundary could be dominant for the electric properties of CNW-FET. Then we will show the noise spectral analysis. The CNW-FET shows 1/f-type noise in a drain-source current. There are two noise resources in the CNW channels. One relates to environmental noise such as molecular adsorption with large surface area, and the second relates to grain boundary scattering. Higher growth temperatures enlarge the grain size in CNWs, and this results in a decrease in carrier scattering at the grain boundary. In this case, the noise derived from the grain boundary might be small and the total 1/f noise becomes small. On the other hand, influenza virus can detect the structure of the ganglioside to infect the specific host. We will use the glycan as the detection molecules in the bio-sensor. However, for the electronic detection, the size of molecules should be small because of the Debye screening. We have tried to estimate the size of sialyllactose
Understanding information processing that achieves predictive motion and its application to robot control
No full textNonlinear Spring Mechanism Using Sliding Supports
No full textA nonlinear spring mechanism is studied using sliding supports. The device has two links that are connected in point receiving a force and other edges of the link are moved along the slide guide-rails which are connected with one spring. It is effective to use large slide angles on supports when a small reaction is needed for large displacement. If small slide angles are used as displacement becomes larger, the reaction force reaches its limit and decreases afterwards
