Technology news
TESTING EQUIPMENT
Torsion Tester Suited for Use with Stents and Other Small Medical Components
A torsion testing system developed by the Materials Test division of MTS Systems Corp. (Ivry-sur-Seine, France) is designed for low-torque, high-rotation applications involving the testing of small material specimens, products, and components. The TorsionMaster has applications in product design, R&D, and off-line quality control.
Lito Mejia, biomaterials and biomechanics market manager at MTS, says that the TorsionMaster system was designed to meet a growing need among medical device manufacturers for small-specimen torsion testing capability. "Medical devices generally require very low forces to test properties such as shear and tensile strength," he notes. But until now, according to Mejia, suitable torsion testing systems were not commercially available. "Customers who wanted a low-torque, high-rotation testing system had to have it custom made or build it themselves," he says.
With a torque capacity of ±20 N-m using standard 20-N-m or 0.2-N-m torque cells, the TorsionMaster system is designed to test such specimens as electronic components, biomaterials, polymers, and wires. The system supports standard test methods for fine wire and medical screws. Other medical applications include tests on pacemaker leads, stents, shape-memory alloys, drug-delivery devices, surgical devices, and packaging.
The test instrument is supplied with collet grips, a digital control system, and a software package for control, data acquisition, and analysis. The system is expected to receive CE marking in May.
MTS manufactures a range of systems for determining the mechanical behaviour of materials, products, and structures, as well as measurement and control products for the automation of manufacturing processes.
LABORATORY EQUIPMENT
Bioanalyzer Features First Commercial Use of Lab-on-a-Chip Technology
An automated desktop system for the analysis of nucleic acids has been released by Agilent Technologies Europe (Meyrin, Switzerland), a subsidiary of Hewlett-Packard Europe B.V. (Geneva). The Agilent 2100 bioanalyzer is reportedly the first commercially available product to incorporate lab-on-a-chip technology.
Designed for use by molecular biologists and biochemists working with polymerase-chain-reaction products or ribonucleic acid preparations, the Agilent 2100 improves the quality of nucleic acid analysis by integrating a range of laboratory processes within a single, compact system. The system carries out sample introduction, fluid handling, and biochemical analysis within the confines of disposable microchips containing interconnected networks of fluid reservoirs and pathways.
Geoff Parnham, European programme manager at Agilent Technologies, says that the system presents several advantages over traditional methods of analysis, including improved accuracy, reproducibility, and speed. He points out that the system requires only 90 seconds to separate and analyze a nucleic acid sample. Conventional analysis, based on gel electrophoresis techniques, typically requires a lengthy separation process followed by separate image-capture and analysis steps. "Another real gain is in the minute sample sizes," Parnham adds. "In the past, some samples couldn't be analyzed because the substance was too precious," he says, noting that the Agilent 2100 can perform analysis using only 1 µl of sample per well.
The system comes with three introductory assays for DNA and RNA analysis and is initially available in Germany, Switzerland, the United Kingdom, and the United States.
LASER WELDING
Bonding Method Creates Invisible Joints in Plastics
Scientists at a British contract research organization have developed a technique for laser welding plastics that creates joints almost invisible to the human eye.
The ClearWeld technique, developed by the Advanced Materials and Processes department at TWI (Cambridge, UK) allows two similar clear plastics to be joined with no visible weld line. The method can be used to weld film, sheet, and moulded plastics, and can be carried out using diode or Nd:YAG lasers in single-shot or continuous-seam welding processes.
Until recently, a dark absorber such as carbon black acted as the medium of heat transfer to create laser welds in plastics. ClearWeld works by using an almost colourless dye that absorbs infrared light and converts it to heat without significantly absorbing visible light. The dye, developed by Gentex Corp. (Carbondale, PA, USA), is applied to one of the components to be welded, either to the surface by painting or printing, or into the bulk of the plastic. It can also be applied in a thin film inserted at the joint. The use of infrared dye as an absorber allows for a low-visibility weld between two materials that need to be clear or have a predefined colour. Previous applications of such dyes include protective eyewear for use with scientific and industrial lasers.
Medical applications of the ClearWeld technique include packaging, tube fittings, fabrics, optical products, and microcomponents. "We are expecting this technique to find niche applications," says Ian Froment, senior project leader at TWI.
Froment explains that ClearWeld can be used in complex designs while producing minimum vibration and heat input. "This makes it suitable for use with sensitive components that may be damaged in traditional welding," he says. Froment notes that the technique's tendency to produce low levels of flash is a further benefit for designers.
TWI developed ClearWeld as part of its ongoing Core Research Programme. The firm holds a patent on the technique and is seeking to license it to interested companies. "This technology is an exciting prospect for us, and we're starting to see some interesting applications," he says, adding that a developing project involves the application of the technique to medical sensors.
