Design and modeling of a multiband electrically coupled loop antenna for biomedical applications

Microsystem Technologies - A triple-band Electrically Coupled Loop Antenna (ECLA) is designed to operate in the three standard bands for biomedical implantation purposes: Medical Implant...     

Design and microfabrication of a flexible oral electrotactile display

A polyimide-based flexible oral tactile display with an array of 7/spl times/7 tactors is designed for presentation of electrotactile patterns onto the roof of the mouth. The device is microfabricated on a rigid substrate using thin-film and electroplating processes and then released by peeling it off from the substrate. Dome-shaped tactors are electroplated through round openings 300 /spl mu/m in diameter in the flexible polyimide base for more uniform current distribution and better contact with the skin. The overall dimensions of the tactor array are 18.5/spl times/18.5 mm/sup 2/, with a center-to-center spacing of 2.54 mm between adjacent tactors. Each tactor is 200 /spl mu/m in height and 700 /spl mu/m in diameter. The device robustness is improved by using a grid-pattern design for the openings to overcome the stress mismatch between the rigid tactors and the flexible base. The flexible oral tactile display has been tested in human subject experiments and found to deliver comfortable electrotactile stimulation with relatively low stimulation intensities.     

Artificial intelligence and deep learning for biomedical applications

Multimedia Tools and Applications -     

Design,closed-form modeling and analysis of SU-8 based electrothermal microgripper for biomedical applications

Microsystem Technologies - This paper presents design analysis of an SU-8 based 2-DoF electrothermal microgripper by developing a closed-form analytical model. The analytical model considers both...     

一种基于硬件的大规模哈希流表设计与实现

基于流的报文处理是防火墙、入侵检测等网络安全应用的重要组成功能,其中流表是流处理技术的关键数据结构,流表的规模及访问性能直接影响到流处理的能力和速度。着眼于高速网络下大规模流表的硬件实现,设计了一种基于硬件的千万级哈希流表查找架构,并在FPGA平台上进行了实现和测试。该方案在保证访存效率的同时很好地解决了冲突的难题,利用有限的存储资源,满足了高达4 900万项的流表查找需求,测试能够实现92Mdesc/s的表查找速度,支持约220Gbps高速以太网的处理能力。     

Dynamic simulation of thermopneumatic micropumps for biomedical applications

A model simulation of dynamic behavior of thermopneumatic micropump is presented. The model uses conservation of energy, mass, and momentum to predict the behavior of existing thermopneumatic micropumps. Applied to existing micropumps, simulation predicts trends similar to those reported experimentally. Dynamic simulation of effect of design parameters on performance of micropump is, then, carried out through the article. Results suggest that increasing operating frequencies results in higher volume flow rates until a critical frequency is reached. At higher frequencies volume flow rates decrease. Critical frequencies are dependent on damping. The higher the damping coefficient the lower the critical frequency becomes. For high frequency operation the performance of the micropump is dominated by both damping and heat capacity of micropump components. For low frequency operation the performance is dominated by heat losses from walls of air-chamber. The model provides general guidelines for building and operating the micropump.     

An overview of magnetic micro-robot systems for biomedical applications

Untethered and wirelessly-controlled micro-robots have been catching substantial attention for a long time due to their great potentials in biomedical areas. Their small sizes and property of wireless magnetic actuation and control make them fit in tiny and closed environments both in vitro and in vivo such as lab-on-a-chip and human blood vessels for micromanipulations, minimum/non-invasive theoretical and diagnostic applications, respectively. In recent years, micro-robots driven by magnetic fields become a hotspot due to their good controllability and motion performance they have shown in both wet and dry environments. And they hardly bring harm under magnetic actuation and control, which qualify them especially for biomedical applications. This paper reviews the state of the art of hjbvmagnetic-micro-robot systems, including the related knowledge and theories, design works of magnetic micro-robots and magnetic navigation systems. For a straightforward understanding, several types of magnetic micro-robot systems are presented. And some applications of magnetic micro-robot systems are introduced at the end to show their great potentials. However, for further developments, many obstacles still need to be solved.     

A novel design and microfabrication for a micro PEMFC

A novel design and microfabrication were developed for a micro Proton Exchange Membrane (PEM) fuel cell with a cross section of 5 cm² and thickness (for a single cell) of about 800 m. A new design and fabrication processes were developed for both flow field plate and MEA parts. Air flows were completed in hydrogen fuel cells with low input pressure and low velocity. Performance tests of polarization curves and power density distribution were conducted and discussed.Part of this work was presented at the first ASME Conference on Fuel Cell Science, Engineering and Technology, April 21–23, 2003, Rochester, New York, USAThis work was performed in University Microsystem Laboratory, Center for Nanoscience and Technology, National Sun Yat-Sen University. The effort is sponsored by the National Science Council (NSC), Taiwan, ROC, Grant numbers NSC 91-2218-E-110-009 and 91-2218-E-110-010.     

High functionality of a polymer nanocomposite material for MEMS applications

We present on a carbon nanoparticle-filled SU-8 photosensitive polymer nanocomposite for use in microelectromechanical systems (MEMS) or microsystems. Exposure and fabrication of the material was carried out using X-ray lithography. The polymer nanocomposite was studied for its electrical, thermal and mechanical characteristics. It was found that at low filler weight percentages, the SU-8 polymer became electrically and thermally conductive. A comparative study of the lithography performance of this functionalized SU-8 to pure SU-8 was also performed. It was determined that UV lithography of the PNC was not suitable for thick films and that by using X-rays, thick film high-aspect-ratio microstructures were achievable. Such results are favorable for many applications such as monolithically integrated polymeric micro-resistive heating elements and polymeric micro-heat sinks.     

Design, microfabrication and evaluation of robust high-performance superlyophobic surfaces

High-performance superlyophobic surfaces (SLSs) showing extremely low wettability for various liquids including water and oil are microfabricated following universal design criteria and formulated rules, and their wetting and hydrodynamic performances are systematically evaluated. Four design criteria are proposed to achieve reliable air-entrapped Cassie-Baxter (C-B) state for various liquids, especially low-surface-tension oils by considering the pressure balance and curvature requirement, as well as the pinning and suspending condition. By formulating the geometric design rules, a T-shaped configuration with a slight undercut is preferred as robust 3D structure for microfabricated high-performance of SLS. The static and dynamic contact angles (CAs) of water and hexadecane on SLS can be well tuned by varying the solid fraction. On the high-robustness and low-adhesion SLS, CAs up to 167° for hexadecane and 170° for water, and low contact angle hysteresis (CAH) ∼ 8° have been achieved. However, CAs on SLS cannot be well explained by three existing wetting models, which requires more efforts to exactly depict the droplet behavior on SLS.     

Design and UV-LIGA microfabrication of an electro-statically actuated power relay

A novel type of micro power relay has been designed and fabricated using UV-LIGA technology. The relay is based on electrostatic actuation and SU-8 was used as a functional material. The unique character of this novel power relay is that other than two SU-8 strips used both as electrical insulators mechanical connectors, all other components are made of metal or alloys. Because UV-LIGA technology has the advantages of broad material selection and the capability of making high aspect ratio microstructures, the technology is best suited for fabricating micro electro mechanical system power relays. A multi-step, multi-layer UV-LIGA process has been successfully developed and a prototype relay has been successfully fabricated.     

鱼鲜度检测仪的设计

鲜度是鱼类可食用性的重要标志。介绍了一种应用三甲胺 (TMA)传感器对鱼鲜度进行测试的方法。它可以实现鱼鲜度的无损实时测量。这种鱼鲜度检测仪电路简单、功耗小、具有较高的实用价值。     

基于双差压式的液体微流检测仪设计

针对现有液体流量计对低流与微流分辨力不够的难点,设计了一种基于双差压原理的新型液体微流检测仪.在单差压传感器的另一侧,接有完全相同的取压管和差压传感器,当液体流过导液管时,会同时在两侧的输入管与输出管之间产生压力差,形成双差压.双差压传感器将导液管入口与出口之间的压力差转换成电压输出,经放大电路放大后送单片机实现A/D转换和信号处理,最后显示出流量值.测试结果表明:该微流检测仪分辨力达到0.1 mL/min,每个流量点的重复性优于0.042％,具有设计原理新颖、结构简单、精度高、量程范围宽等优点.     

A water-tight packaging of MEMS electrostatic actuators for biomedical applications

This paper presents a flip-chip based packaging technique for encapsulating MEMS electrostatic actuators for biomedical applications. High-performance electrostatic inchworm actuators are used to demonstrate the packaging technique. A wall structure is put around the actuator surrounding it completely but leaving a small clearance where the actuator shuttle can extend off the edge of the chip. A cap chip is fabricated separately, and flip-chipped onto the actuator. Au–Au thermal bonding technique is used to fix the cap. Finally, rendering the surfaces of the clearance hydrophobic prevents the water ingress when the actuator operates in water.     

A fast and effective ellipse detector for embedded vision applications

Several papers addressed ellipse detection as a first step for several computer vision applications, but most of the proposed solutions are too slow to be applied in real time on large images or with limited hardware resources. This paper presents a novel algorithm for fast and effective ellipse detection and demonstrates its superior speed performance on large and challenging datasets. The proposed algorithm relies on an innovative selection strategy of arcs which are candidate to form ellipses and on the use of Hough transform to estimate parameters in a decomposed space. The final aim of this solution is to represent a building block for new generation of smart-phone applications which need fast and accurate ellipse detection also with limited computational resources.     

Development and evaluation of a scale for measuring practitioners' attitudes toward computer applications

This paper describes the development and evaluation of a scale designed to measure practitioners' general attitudes toward clinical computer applications — the Practitioners' Attitudes Toward Computer Applications Scale (PATCAS). The PATCAS contains 35 items linked to seven structural variables. Results of a study of 227 practicing psychologists indicated that the PATCAS showed several desirable properties. Internal consistency was satisfactory for the seven PATCAS scales and excellent for the total score, and intercorrelations among the seven scales were moderately high. In terms of validity, the PATCAS was found to be related to several measures of computer use. Finally, scores on the PATCAS were found to be related to practitioner characteristics including sex (men's attitudes toward computers were generally more favorable than women's), theoretical orientation, and work setting. Suggestions are made for appropriate applications of the PATCAS.     

输油管道微小泄漏球形检测器的设计与实现

针对输油管道微小泄漏检测方法有限、检测成本高、阻塞管道风险大等问题,提出了新的解决方案:设计了一个基于ARM—Linux和MEMS传感器的球形管道内检测器,其直径小于待检测管道直径。详细论述了该检测方案的原理、球形检测器的硬件组成、软件设计等内容。通过在输水管道内的多次模拟泄漏实验,证明该球形检测器检测流程简单、运行安全,能有效地检测出泄漏并给出较精确的定位信息,为输油管线微小泄漏的高精度、低成本的实用检测提供了有力的技术支持。     

Design and fabrication of 3-dimensional helical structures in polydimethylsiloxane for flow control applications

Soft lithography in 2-dimensional (2-D) was developed for polymer MEMS applications about two decades back. The technique was highly useful for replication of microstructure molds using a soft polymeric material called PDMS (polydimethylsiloxane). From its inception the process has been widely applied to microfluidics, biochips, hybrid biomedical microdevices etc. However, it was limited to only surface microstructures and 3-Dimensional (3-D) soft lithography although performed by some research groups involved some very precise and expensive techniques like stereolithography etc. The exploration of soft lithography in three dimensions by using a replication technique with copper wires with micron size diameters was performed by our group relatively recently (Singh et al. in International conference on MEMS, IIT Madras, Chennai, 2009). In this work we have used the 3-D replication and molding technique to develop concentric solenoid patterns around micro-channels in the bulk of PDMS. The solenoidal paths of various pitches ranging from 0.4 to 1.2 mm have been replicated in PDMS using an innovatively designed fixture. The solenoids have been structurally characterized using an inverted fluorescence microscope (Nikon 80i) for dimensional parameters like pitch, length etc. Further, the solenoidal path designs have been simulated, optimized and fabricated around a central channel of 80 μ diameter and we have observed the repeatability of this fabrication process multiple times. The purpose of this architecture is to initiate valving action wherein fluid movement in the central channel can be restricted by filling the surrounding solenoidal track with compressed air at high pressure so that it can squeeze the centrally located micro-channel carrying the liquid. This valving structure may find a lot of applications in lab on chip devices, PCR biochips, biomedical micro-devices etc.     

Design and simulation of a novel flip-chip structure for THz detector package

Microsystem Technologies - This work is intended to describe the design aspects and to characterize the functionality of a novel flip-chip (FC) structure applicable for THz camera assembling. The...