Commercially available technologies are limited in their resolution (≥100 µm) and some also in their material properties.
Two important requirements exist for electromagnetic metamaterials: 1) a higher resolution is required; and 2) the use of both conductive and isolating materials is required.
Currently no 3D Printing technology exists that fulfils the requirements of both the resolution and the material parameters (conductivity). One could manufacture the metamaterial using technology from the semiconductor industry. However, these manufacturing technologies are too slow, or the required metamaterial products have a volume that is to large.
Furthermore, within TNO we already have expertise on vat photopolymerisation, on screen printing conductive pstes and on novel structures for advanced antennas.
Metamaterials in general are of great interest since it gives access to unique material properties that were previously not available, which in turn can be applied in all kinds of technologies where for example electromagnetic radiation, or vibrations play a role. An example of a new application using metamaterial is the possibility to produce lenses with optical properties that go beyond conventional lenses and mirrors. The use case targeted here is for use on radar systems to increase the viewing angle. The technology developed here can have wider applications, producing other metamaterials and embedded electronics.
Process development for multi-material additive manufacturing for embedded conductive tracks with structures of 100 µm, and a conductivity of 10% copper bulk conductivity, leading to a functioning metamaterial for radar applications.
The Lepus Next Gen machine for large area multi-material vat photopolymerisation for large area printing with a resolution of 20 micron.