Pinpoint injection of microtools for minimally invasive micromanipulation of microbe by laser trap

This paper reports transportation of the target microbe by the laser trapped microtools with minimum laser irradiation to the target. The size of a microtool (MT) is around micrometer. The MTs are manipulated by the focused laser under the microscope to manipulate the target microbe. Here we propose a pinpoint injection method of MTs at the desired location in the microchamber, which is filled with liquid. At first, we classified the injection method of the MTs in four categories. Here we employed a new method to install the MTs inside the microchamber. We developed a MT holding chip to install the MTs. The MTs were injected in the microchamber, and were manipulated successfully by the laser scanning micromanipulator to transport the target microbe for separation. The proposed method is useful for the pinpoint injection of MTs and separation by the indirect micromanipulation.     

Supermedia-enhanced Internet-based telerobotics

This paper introduces new planning and control methods for supermedia-enhanced real-time telerobotic operations via the Internet. Supermedia is the collection of video, audio, haptic information, temperature, and other sensory feedback. However, when the communication medium used, such as the Internet, introduces random communication time delay, several challenges and difficulties arise. Most importantly, random communication delay causes instability, loss of transparency, and desynchronization in real-time closed-loop telerobotic systems. Due to the complexity and diversity of such systems, the first challenge is to develop a general and efficient modeling and analysis tool. This paper proposes the use of Petri net modeling to capture the concurrency and complexity of Internet-based teleoperation. Combined with the event-based planning and control method, it also provides an efficient analysis and design tool to study the stability, transparency, and synchronization of such systems. In addition, the concepts of event transparency and event synchronization are introduced and analyzed. This modeling and control method has been applied to the design of several supermedia-enhanced Internet-based telerobotic systems, including the bilateral control of mobile robots and mobile manipulators. These systems have been experimentally implemented in three sites test bed consisting of robotic laboratories in the USA, Hong Kong, and Japan. The experimental results have verified the theoretical development and further demonstrated the stability, event transparency, and event synchronization of the systems.     

Low-temperature sintering of ZrW2O8–SiO2 by spark plasma sintering

Amorphous ZrW₂O₈ powder and amorphous SiO₂ powder were prepared by a sol–gel process as raw materials, and high-density ZrW₂O₈–SiO₂ were successfully prepared at a much lower temperature of 923 K for a much shorter holding time of 10 min by spark plasma sintering (SPS) method rather than by conventional melt-quenching method. The relative densities of 0.85ZrW₂O₈–0.15SiO₂ and 0.70ZrW₂O₈–0.30SiO₂ were 99.4% and 96.6%, respectively. The combined technique of a sol–gel process and SPS should enable us to prepare the varied types of high-density composites of ZrW₂O₈ without severe thermal cracking caused by melt-quenching. The thermal expansion properties and dielectric properties of ZrW₂O₈–SiO₂ were also investigated.     

β核磁共振和β核四极共振谱仪

为了开展核物理、粒子物理和凝聚态物理方面的研究 ,在中国原子能科学研究院建成了 1台 β核磁共振及 β核四极共振谱仪。利用该谱仪精确测量了12 B的极化度和12 B基态磁矩 ,所测量的12 B在Cu中的极化度为 1 1 4%± 0 6% ,12 B磁矩 μ =1 0 0 0 2± 0 0 0 2 8nm。实验应用证实该谱仪性能可靠。     

Surface modification of poly(3,4-ethylene dioxthiophene):poly(styrene sulfonic acid) (PEDOT:PSS) films by atmospheric-pressure argon plasma for organic thin-film solar cells

Highly-conductive poly(3,4-ethylene dioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) films obtained by the addition of dimethylsulfoxide (DMSO) and the argon plasma exposure were used as a transparent conductive anode (TCA) for copper-phthalocyanine (CuPc)/C60 organic thin-film solar cells (OSCs). The CuPc/C60 OSCs on as-grown DMSO added PEDOT:PSS layer showed a power efficiency of 0.6%, whereas it was improved markedly to 1.34% after the atmospheric-pressure argon plasma exposure, which was comparable to that formed on indium-tin-oxide layer. Effects of the DMSO addition and the argon plasma exposure in the spin-coated PEDOT:PSS films is demonstrated in terms of the in-depth characterization of optical and electrical properties.     

Fabrication of magnesium based composites reinforced with carbon nanotubes having superior mechanical properties

Magnesium (Mg) composite reinforced with carbon nanotubes (CNTs) having superior mechanical properties was fabricated using both pure Mg and AZ61 Mg alloy matrix in this study. The composites were produced via powder metallurgy route containing wet process using isopropyl alcohol (IPA) based zwitterionic surfactant solution with unbundled CNTs. The produced composites were evaluated with tensile test and Vickers hardness test and analyzed by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) equipped with energy dispersive spectroscopy (EDS) and electron back scattered diffraction (EBSD). As a result, only with AZ61 Mg alloy matrix, tensile strength of the composite was improved. In situ formed Al₂MgC₂ compounds at the interface between Mg matrix and CNTs effectively reinforced the interfacial bonding and enabled tensile loading transfer from the Mg matrix to nanotubes. Furthermore, it was clarified that the microstructures and grain orientations of the composite matrix were not significantly influenced by CNT addition.     

Nanofork for single cells adhesion measurement via ESEM-nanomanipulator system

In this paper, single cells adhesion force was measured using a nanofork. The nanofork was used to pick up a single cell on a line array substrate inside an environmental scanning electron microscope (ESEM). The line array substrate was used to provide small gaps between the single cells and the substrate. Therefore, the nanofork could be inserted through these gaps in order to successfully pick up a single cell. Adhesion force was measured during the cell pick-up process from the deflection of the cantilever beam. The nanofork was fabricated using focused ion beam (FIB) etching process while the line array substrate was fabricated using nanoimprinting technology. As to investigate the effect of contact area on the strength of the adhesion force, two sizes of gap distance of line array substrate were used, i.e., 1 μm and 2 μm. Results showed that cells attached on the 1 μm gap line array substrate required more force to be released as compared to the cells attached on the 1 μm gap line array substrate.     

High-intensity multi-bunch beam generation by a photo-cathode RF gun

A multi-bunch photo-cathode RF gun system has been developed as an electron source for the production of intense quasi-monochromatic X-rays based on inverse Compton scattering. The desired multi-bunch beam is 100 bunches/pulse with a total charge of 500 nC and a bunch spacing of 2.8 ns. We modified the gun cavity of a ‘BNL-type IV’ RF gun to allow a CsTe cathode plug in the end plate. The system uses a four-dipole chicane beam line to allow the injection of laser light normal to the cathode surface. We compensate the gun cavity beam loading caused by the high-intensity multi-bunch electron beam by injecting the laser pulse before RF power has filled the cavity. We have achieved a total intensity of 220 nC in 100 bunches with a bunch-to-bunch energy spread under 1.3% (peak-to-peak). This paper concentrates on experiments to generate the high-intensity multi-bunch beam with compensation of the bunch-to-bunch energy spread due to heavy beam loading.     

Ultrathin Organic Electrochemical Transistor with Nonvolatile and Thin Gel Electrolyte for Long‐Term Electrophysiological Monitoring

Skin‐based electrical‐signal monitoring is one of the basic and noninvasive diagnostic methods for observing vital signals that contain valuable information about the dynamic status of the inner body. Soft bioelectronic devices are developed for the acquisition of high‐quality biosignals by taking advantage of their inherent thin and soft bodies. Among these devices, the organic electrochemical transistor (OECT) is a promising local transducing amplifier because of its key advantages, such as low operating voltage, high transconductance, and biocompatibility. However, the transistor's direct electrolyte‐gated operation limits its ability to measure biosignals only when the electrolyte exists. Here, an ultrathin OECT‐based wearable electrophysiological sensor based on a thin (≈6 µm) and nonvolatile gel electrolyte is reported, which can operate on dry biological surfaces. This sensor can measure biopotentials with a high mechanical stability and high signal‐to‐noise ratio (24 dB) even from dry surfaces of the human body and also shows stable performance during long‐term continuous monitoring and multiple reuse in a test that lasted more than a week.     

Effects of phosphorus content on generation and growth of cracks in nickel–phosphorus platings owing to thermal cycling

We observed crack generation and structural changes in electroless nickel–phosphorus (Ni–P) plating layers formed on copper-metalized silicon nitride substrates both during thermal cycling from ? 40 to 250 °C and during storage (not cycling) at 250 °C in order to investigate the effect of the phosphorus contents on crack generation and growth in the Ni–P platings. The used platings contained phosphorus at three different contents: 2.1 wt% [Ni–P(low)], 6.5 wt% [Ni–P(med)], and 10.9 wt% [Ni–P(high)]. The generation time and the amount of cracks were strongly dependent on their phosphorus contents. More cracks appeared after thermal cycling than after storage at 250 °C. In Ni–P(low), cracks were generated after 200 thermal cycles, whereas no cracks were observed even after 250 h of storage at 250 °C. In Ni–P(med) and Ni–P(high), both during thermal cycling and storage at 250 °C, cracks formed during or after crystallization of the amorphous layers. These results suggest that the primary factors affecting the generation of cracks in electroless Ni–P platings are crystallization of the Ni–P platings and repeated changes in thermal stress.