Technology News
PRODUCT DEVELOPMENT
Innovative Process Facilitates Building of Complex Microstructure Components
A process that enables the production of 3-D microstructures using stereolithography technology facilitates the integration of miniature components by means of generative growth in layers down to 1 µm. Rapid Micro Product Development (RMPD), a proprietary process developed by microTEC Gesellschaft für Mikrotechnologie mbH (Duisburg, Germany), offers new opportunities for layout and connection operations, says product manager Reiner Götzen.
"Microelectronic, microoptical, and micromechanical components can be connected very simply to build complex microsystems," says Götzen. "Traditional microstructuring processes cannot produce component layouts." He adds that this capability is one of the advantages of RMPD technology. "It enables innovations in microsystem techniques, can spur the development of new products, and provides a means to miniaturize existing products."
The process involves converting a virtual CAD model to a prototype that is built from a liquid monomer, which is then polymerized by exposure to a laser. A prototype can be produced from the CAD model within 24 hours, according to Götzen, and the technology also allows for short production runs. The products can also be metal plated.
The development of a flow sensor illustrates some of the benefits of this technology which, according to Götzen, has potentially wide-ranging applications in the medical device industry. "The microTEC flow sensor integrates not only mechanical components, such as those typically used in the watchmaking industry, but also fibre-optic waveguides. The device is able to measure flow in very small spaces, with impellers and wind wheels that are less than 1 mm in size, for example," says Götzen. Currently, the flow sensor measures 2.2 mm diam and 3 mm long and the wind wheel is 1.6 mm diam, but the technology will allow for further miniaturization, he adds.
MicroTEC's core mission is to assist clients in the development of functional microsystems, from the initial development stage to the point at which serial production can begin. In addition to its RMPD technology, the firm offers engineering services, product management, grants counseling, research partnerships, and technology feasibility studies.
MATERIALS
Acrylic-Based Multipolymer Helps Reduce Visible Contaminants
Cyro Industries (Rockaway, NJ, USA), a manufacturer of acrylic and polycarbonate sheet as well as acrylic moulding and extrusion compounds, recently introduced an acrylic-based multipolymer compound that helps reduce visible contaminants in disposable medical devices. Cyrolite G20 EF offers medical device manufacturers a clean, clear, and impact- and gamma-resistant resin that can be easily processed.
"Certain medical device markets require extremely clean material," says the company's technical manager Peter Colburn. "The cleanliness of Cyrolite G20 EF allows it to be used in medical device applications in all markets."
The Cyrolite G20 EF compound is produced using a proprietary closed-loop filtering process that permits continuous monitoring and ensures cleanliness to 40 µm. Because the resin is exposed only to filtered air, impurities are eliminated to fewer than 60 parts per billion. Compatible with gamma, EtO, and E-beam sterilization methods, the resin has been designed for such uses as disposable filters, IVs, IV pumps, and blood-handling devices.
Cyro products are supplied through Röhm GmbH (Darmstadt, Germany).
MANUFACTURING EQUIPMENT
Laser System Reengineered to Perform Intricate Drilling and Cutting
A laser machining system developed for welding applications by Lumonics (Unterschleissheim, Germany) has been reengineered for use in fine cutting and drilling operations. Originally designed for integration with fibre-delivered lasers, the system is now available with direct beam delivery, which allows the laser beam to be focused to precise spot sizes measuring 0.025 mm diam and smaller. This capability makes the system suitable for processing complex medical parts such as coronary stents, tip catheters, and cannula housings and sleeves.
"The Laserdyne 140 was designed for prototype and small-batch welding of components used in pacemakers and so forth," says Lumonics's Scott White. "We soon realized that the basic premise of the machine with the same controller but a different laser could be used for precision cutting." Direct beam delivery uses precision mirrors and focusing optics to direct the laser beam to the workpiece in spot sizes that are unattainable by means of fibre delivery.
The Laserdyne 140 comprises a three-axis CDRH Class I laser workstation and a Laserdyne System 94/PC laser process control that operates with a standard industrial PC and operating system. All laser, motion, and process conditions can be controlled by means of a keyboard or from within the part programme. Programming features include variables, subroutines, beam radius compensation, character generation, and axis and plane rotation; CAD/CAM programmes can be imported either by floppy disk or via an RS-232C interface. The system is equipped with a 32-bit control designed specifically for multiaxis laser machining. When an optional rotary table is added, three-dimensional parts can also be machined.
Laser systems for precision cutting and drilling have several advantages over more traditional methods, according to White. "Micromachining is a growing area in medical," says White, "so you're getting into a range where a laser machining process can be more economical than conventional mechanical or EDM operations." Other technologies can accomplish the same goals, according to White, but lasers can do it faster and with greater consistency. Chemical etching can be economical for large batches, adds White, "but most people in this industry may do 20 or 100 pieces at a time. That's where the flexibility of a laser offers a substantial advantage."
Lumonics develops, designs, manufactures, and supplies turnkey laser systems for cutting, welding, marking, and machining to medical device companies worldwide. All of the company's equipment carries the CE mark.
