Background
Radar cross section (RCS) is a measure of the portion of an object’s surface area that can be detected by radar. A higher RCS means better visibility for radar detection systems. Conductive paints – used to shield circuits from incoming electromagnetic and radio frequency interference (EMI/RFI) – reflect incoming signals, which engineers are now harnessing to help radar systems pick up and amplify the visibility of moving objects. Treating ordinary plastics and composites with electrically conductive coatings that have a smooth finish helps detection systems like LIDAR (used in autonomous vehicles) receive reflected signals, so that moving objects such as cyclists become more visible.
Customer Challenge
One of our customers had to find a product that achieved a high RCS (measured in decibels relative to square meters, or dBsm) at distances of up to 50m, for a small nylon carbon fiber part mounted on a bicycle.
Key Requirements
- High electrical conductivity
- Smooth surface finish
- Adhere well to a variety of substrates, such as nylon carbon fiber
Solution
MG Chemicals 842UR is a 1-part, electrically conductive coating that adheres to a wide variety of substrates. It uses a specially engineered silver flake with a high aspect ratio (high surface area relative to thickness) to help achieve a very smooth cured film that can be applied very thinly (about 8 microns). The customer was able to apply this coating onto a nylon carbon fiber part about the size of a tennis ball and achieve consistent RCS readings of 15 dBsm, with measurements as high as 19 dBsm, which exceeds bare aluminum.
Conclusion
While electrically conductive coatings effectively reflect signals off their surface to prevent unwanted transmission of EMI/RFI, those reflected signals can be captured by radar systems, such as those in autonomous vehicles, to help make moving objects more visible. Electrically conductive coatings like MG’s 842UR contains a specially engineered silver flake which renders the cured surface both highly conductive and smooth. These properties can help achieve consistent RCS values of 15 dBsm from a distance of 25m.
