One notable area of research currently underway at Fraunhofer IFAM is in radio frequency identification (RFID) applications as used in logistics, especially for the purpose of tracking and managing items. Of current focus is the real-time tracking of medical instruments during a surgical operation. The metallic environment in the operating room represents a big challenge, hampering the readability of the RFID tag. Currently transponders are joined to metal instruments by bonding or clamping inside a polymer shell, containing as little metal as possible.
Assembling the tags is a time-consuming process, which changes the usual shape of the instrument. It also represents a point of failure, because of the possibility of losing the tag during the instrument’s life cycle. AM can be used to integrate the entire RFID tag in a metallic instrument while keeping the original shape. Research shows that it is possible to read RFID tags through a closed SLM metallic casing.
Successful research has been done with tags in the low frequency (LF) range. Instrument manufacturing by AM enables small wall thicknesses and a reduced temperature impact on the RFID tag during the building process. Tag integration in complex parts and readability through metal open a new dimension in the traceability and manufacturing of medical devices.
Integration of electronics in polymers
Similar research activities for the integration of electronics in polymers have been done at Fraunhofer IZM. Electronic components have been embedded in a substrate, which is manufactured using direct digital manufacturing processes. In the initial step, an assembly is manufactured, in which selected planar components are embedded, including SMD resistors, capacitors, LEDs and a microcontroller.
In the areas of material development, biomimetic, cellular materials (lattice structures) and of course process development there are groups around the world working on new ideas. For laser-based processes there are approaches to avoid residual stresses during processing by working at higher temperatures or to get better surfaces by utilisation of pulsed lasers.
Hybrid and multi-material processes offer new possibilities for industry and medical applications. On the software side some efforts are allowing faster data preparation and the use of more complex geometries with higher data volumes. Simulation software could reduce the time needed for qualifying new materials and also predict some distortions during process, being an area of major interest for research activities.
Processing of scandium
An investigation at EADS Innovation Works in cooperation with the Hamburg University of Technology shows the tremendous benefits of scandium regarding the combination of high-strength properties with a reduction of density. The improvements of properties that can be achieved by adding this element to an Al alloy are impressive. The rapid solidification offered by the SLM process allows for cooling rates that are sufficient to keep all alloyed scandium in a hypereutectic Al–scandium composition. This produces high strength properties, around 500 MPa, with nearly isotropic results. Furthermore, the ductility of the additively manufactured material, with an elongation of 14% and reduction of area 20%, is remarkable.