A5012870459- Advanced MEMS and NEMS Technologies
- Microfluidic and Capillary Electrophoresis Applications
- Force Microscopy Techniques and Applications
- Mechanical and Optical Resonators
- Electrowetting and Microfluidic Technologies
- Adhesion, Friction, and Surface Interactions
- Analytical Chemistry and Sensors
- Carbon Nanotubes in Composites
- Concrete Corrosion and Durability
- Microfluidic and Bio-sensing Technologies
- Nanopore and Nanochannel Transport Studies
- Electrical Contact Performance and Analysis
- Microwave Engineering and Waveguides
- Diamond and Carbon-based Materials Research
- Innovative Microfluidic and Catalytic Techniques Innovation
- Tribology and Wear Analysis
- Metal and Thin Film Mechanics
- Tropical and Extratropical Cyclones Research
- Smart Materials for Construction
- Molecular Junctions and Nanostructures
- Ecosystem dynamics and resilience
- Semiconductor materials and interfaces
- Graphene research and applications
- Complex Systems and Time Series Analysis
- Copper Interconnects and Reliability
Future Earth
2022
National Physical Laboratory
2017-2020
University of Southampton
2008-2018
Louisiana State University Agricultural Center
2011
University of Bath
1986
Capillary electrophoresis (CE) is a technique which uses an electric field to separate mixed sample into its constituents. Portable CE systems enable this powerful analysis be used in the field. Many of challenges for portable are similar those autonomous in-situ and therefore may considered stepping stone towards analysis. widely biological chemical example applications include: water quality analysis; drug development control; proteomics DNA counter-terrorism (explosive material...
The modeling of energy components in wireless sensor network (WSN) simulation is important for obtaining realistic lifetime predictions and ensuring the faithful operation energy-aware algorithms. use supercapacitors as stores on WSN nodes increasing, but their behavior differs from that batteries. This paper proposes a model supercapacitor store based upon experimental results, compares obtained results to those using an 'ideal' model. proposed also considers variety consumers, finds...
Wear processes of the switching contact pair consisting a gold layer on multiwall carbon nanotubes (Au/MWCNT) and chromium coated hemispherical ball (Au/Cr) are evaluated over range current conditions. The experiments were conducted using typical conditions for MEMS relay application, i.e. 4 V, with static force 1 mN currents level 20-200mA. Au MWCNT substrate exhibited transfer process large number cycles. On assumption that was combination fine delamination processes; previous experimental...
A bi-layer metal-carbon nanotube composite has been developed as a potential low-force electrical contact surface, for application in micro-electromechanical systems switching devices. The samples consist of vertically aligned forest multi-walled carbon (MWCNT), sputter coated with layer Au. effect varying the components and composition are investigated by means modified nano-indenter. By measuring resistance composites under various loading conditions, properties performance can be...
Spatially explicit, near real time information on surface water dynamics is critical for understanding changes in resources, and long-term security planning. The distribution of across the African continent since 1984 updated as every new Landsat scene becomes available presented here, validated first time. We applied Water Observations from Space (WOfS) algorithm, developed well-tested Australia, to acquired over Africa mid 1980s provide spatial past 30+ years. assessed accuracy WOfS using...
Gold is commonly used for electrical contacts due to its many desirable and mechanical properties. Throughout the switch lifetime, are required survive a large number of opening closing cycles therefore it important understand failure mechanisms. Adhesion layers (e.g. chromium or titanium) can be deposited increase adhesion gold layer contact surface. In this work, inclusion shows an improvement switching lifetime gold-coated under cold hot conditions. These testing conditions further...
Gold is commonly used for microelectromechanical electrical contacts due to its desirable and mechanical properties; however, the lifetime of gold limited, particularly in case hot switching. To improve contacts, we have developed a gold-coated multiwalled carbon nanotube bilayer composite. Experiments with these composites shown that switching dynamics vary over switch. The change potential across switch during contact-break process, referred as transient opening voltage, has been monitored...
An increase in the market growth of conductive inks for flexible and printed electronics is predicted to from $2.3 billion $3.2 by 2025 (Savastano 2015 Printed Electronics Now). For quality process control, order maintain output yield reduce waste, it critical that we are able verify electrical properties electronics. This work explores a non-contact technique developed measure structures during manufacture roll-to-roll process. Inductive sensors used response electrically samples. The...
A gold coated carbon nanotubes composite was used as a contact material in Micro-Electrical-Mechanical-System (MEMS) switches. The switching tested under typical conditions of MEMS relay applications: load voltage 4 V, force 1 mN, and current varied between 20-200 mA. This paper focuses on the wear process over lifetime, dependence area is discussed. It shown that going to fail when approached whole area, at which point resistance increased sharply three times nominal resistance.
The use of gold-coated multi-walled carbon nanotube (Au/MWCNT) composites have been shown to extend the life electrical contacts, in previous work. Due long lifetimes (which are order 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> up xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> cycles) lifetime testing tends be highly time consuming. In this work we discuss design and development an electrostatically actuated MEMS cantilever...
Earth observation of waterbodies through time is a powerful tool in understanding both the location and their temporal dynamics. Water Observations from Space (WOfS), developed well-tested Australia, service providing historical surface water observations derived Landsat satellite imagery 1987 to present day. WOfS provides better where usually present; it seldom observed; inundation has been occasionally observed by satellite. We applied algorithm Africa validated its accuracy image...
The low level of contact force, typical <;1mN, used in MEMS switches or relays, is often inferred from computational models based on the design geometry device. In this work we propose two methods to measure force. combine experimental measurements cantilever beam displacement with models. Further analyze resistance a fixed and compliant surface. surface Au coated Si, while carbon nanotube designed for electrical force sensing applications.
Gold coated Multi-Walled Carbon Nanotube (MWCNT) composites have been used for electrical contact surfaces in previous studies. It was shown that the composite could significantly improve switch lifetime, and exhibited potential as a useful material MEMS switches. The reason is attributed to contribution of compressibility MWCNT forest, which creates compliant layer under gold films. In this study, experiments were performed samples with different heights forests, namely 30 μm, 50 μm 80 μm....
The use of gold-coated multi-walled carbon nanotube (Au/MWCNT) bilayer composite surfaces has been discussed in previous work as a method for improving the reliability switch contacts [1, 2]. A consequence large lifetimes means that testing to failure is time consuming. To address this we developed MEMS-based test platform which enables at high frequency [3]. MEMS devices were two stage process. In paper results obtained from first design device are discussed. Further this, an overview...
The capillary/channel length is an important factor in capillary electrophoresis (CE) systems since it directly related to the amount of separation attainable. In this work we present methods increase effective channel without need modify physical length. Using electrode located close surface possible dynamically zeta-potential and therefore electroosmotic flow (EOF). By controlling EOF, certain ionic species within a sample can be held short whilst other migrate along channel. Alternatively...