November 29, 2004 Miniaturised components are used in bio-technology, surgery, optics, neuro-physiology and other developing fields that rely heavily on micro-technology. Cost-effective and rapid production of high-resolution three-dimensional micro-structures is now possible all the way down to the sub-nanometer range thanks to Rapid Micro Product Development (RMPD), a generative production method developed by German company microTEC.
RMPD is part of the burgeoning field of "biomimetics", where the processes refined over millions of years by nature are applied for increased efficiency in human systems.
In the past, small, precision plastic components were manufactured by injection moulding - where only a small number of components could be manufactured concurrently using the same equipment - or by laser cutting, which requires subsequent work steps and additional technical equipment. With RMPD technology miniaturised components can now be literally grown to demand specifications in large or small production runs from molten plastic without the aid of tooling. Moreover, only generative processes automatically produce surface properties such as hydrophilic areas, thus avoiding subsequent processing.
The component is built up in layers up to 1µm and a resolution in any direction of up to 10µm. The minimum component size can be 1x10x10µm and is currently limited to a maximum of 50x50x50mm. During the growth of the process several mechanical parts are inserted to achieve the desired functionality.
With RMPD, it has become possible to create channels in all three spatial directions, a big advantage for the realisation of fluidics and biotechnical applications. Optical applications can also be developed like fibre-connectors and optical switches and medical products like biochemical sensors or fluidic structures. Other components like micro-optics and microelectronics can be integrated during the production process, which can have important output for medical applications, successful miniaturisation in sensor technology, optics and telecommunications. Miniature diagnostic devices and micro-structured plastic chips for medical analysis are all possible with RMPD technology, and have offer advantages such as quicker analysis results, smaller volumes of probes and chemicals, and better patient care.
At the EuroMold World Fair for Moldmaking and Tooling, Design and Application Development, which takes place in Frankfurt-am-Main on December 1-4, engineers will present a prototype of the RMPD system to industry users for the first time. “This year, we are focusing on rapid techniques for medical applications,” states Rudolf Meyer, who coordinates the Fraunhofer Alliance for Rapid Prototyping. “A quarter of the projects conducted by the twelve participating institutes and associated small firms fall into this category – and this trend is rising.” One example is the titanium bone implants manufactured by laser melting of successive layers of metal powder, to a tolerance of 0.1 millimeters. "In this area of prosthetics, the tendency is towards increasingly small dimensions and better surface roughness," states Wilhelm Meiners of the Fraunhofer Institute for Laser Technology ILT. "This allows new bone tissue to grow faster and adhere more firmly."
Metal and ceramic parts can be produced in the combination of RMPD with other technologies (like MIM), but RMPD itself only processes plastics.
Technical Insights of San Antonio, TX expects the worldwide market for micro arrays, micro fluidics devices and other biochips to grow at an annual rate of 65%, up to US $3.3 billion by the end of 2004.