A strip of aluminum — the surface of which has been treated with an electrochemical etching process — is permanently bonded with thermoplastic by heating. (Julia Siekmann/Kiel Universit)

How metals can be used depends particularly on the characteristics of their surfaces. A research team at Kiel University has discovered how they can change the surface properties without affecting the mechanical stability of the metals or changing the metal characteristics themselves. This fundamentally new method is based on using an electrochemical etching process, in which the uppermost layer of a metal is roughened on a micrometer scale in a tightly-controlled manner.

Through this “nanoscale-sculpturing” process, metals such as aluminum, titanium, or zinc can permanently be joined with nearly all other materials, become water-repellent, or improve their biocompatibility. The potential spectrum of applications of these “super connections” includes the ability to develop safer medical implants. Because the “nanoscale-sculpturing” process not only creates a 3D surface structure, which can be purely physically bonded without chemicals, the targeted etching can also remove harmful particles from the surface, which is of particularly great interest in medical technology.