TNO studies and develops new, and improves existing, Rapid Manufacturing (RM) processes, some of which use inkjet technology to make 3D products. The print heads used are able to process liquids with a viscosity of up to 30 mPa's. We developed a print head capable of processing high-tech materials with a viscosity of up to 500 mPa's at room temperature into 3D products.
Within the European Custom Fit project, various parties are working on new RM processes for unique product manufacture where by the product can be fully customised to suit individual needs. TNO is focusing on developing a process, high-viscous inkjet printing, able to manufacture custom-made implants of bio-compatible and bio-degradable material. The ultimate goal of this project is to make a jaw implant from a material in which the body's own bone can grow. The implanted material can then be broken down by the body. In order to stimulate cell growth in the implant selective growth stimulators can be added. However, the same kind of cell is not desirable everywhere and cell growth must not be stimulated equally throughout. Therefore, at every position in the implant a specific amount of growth stimulator has to be added. In RM terminology, this application of a gradient in the materials is referred to as multi material manufacturing.
To be able to construct such 3D products a machine is required that is capable of selectively and simultaneously printing a number of different high-tech materials that can harden. In order to model these products, we have created InnerspaceTM, a CAD program that is able to define materials in a 3D product and translate this into data that are suitable for an RM machine. The machine we have developed has three print heads that can selectively deposit various UV-hardening materials next to each other on a moving stage at a frequency of 20 kHz. The print head that processes this high-viscous material has been fully developed and patent protected by TNO. The development process has come to the optimisation phase. We are now able to make a graded 3D product. We are currently working on improving the accuracy and speed of the process. The next step is to fins a commercial party with whom we can work to ramp a working concept up to industrial-scale application.
Our contract research offers companies added value in various ways in the fast growing RM field. Our knowledge of the printing process and the applicable materials is a guarantee for:
We can investigate the suitability of your material for use in commercially available printing systems and, where appropriate, modify your material so that it can be used.