3-D Structure of Metal Surface (IMAGE) Kiel University Caption The targeted etching process of "nanoscale-sculpturing" roughens the upper layer of metal (here aluminium, 20 μm = 0.02 mm), thereby creating a 3-D structure with tiny hooks. A surface treated with this process can inter-lock like a three-dimensional puzzle with the surfaces of almost all other materials, forming unbreakable bonds. With this method, it is even possible to create bonds between aluminum and copper. Credit Melike Baytekin?Gerngross Usage Restrictions The image may only be used with the credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.