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technology report online, March 2016

From more autonomy for quadriplegic patients to high-resolution, ocular prostheses for visual impairment, the new CerMet technology from Heraeus makes it possible.

Three questions for Dr. Robert Dittmer, project manager at Heraeus Medical Components.

Dr. Robert Dittmer, project manager at Heraeus Medical Components
Dr. Robert Dittmer, project manager at Heraeus Medical Components

What makes CerMet unique?

Medical components have to function reliably in the human body for a long time, sometimes for decades. So the demands placed on the materials that are used to manufacture them are correspondingly high. For example, they have to be bio-compatible and hermetically seal the electrical components inside the implants, which are being made smaller and smaller. Our CerMet material is made of ceramic and platinum, and it meets precisely these high requirements. The new material also enables the insertion of electrically conductive channels in an electrically insulating ceramic matrix. This will make it possible in the future to manufacture more compact, robust and powerful medical products with much smaller electrical connections.

The extremely robust CerMet material is a combination of tiny platinum and aluminum oxide particles. Ceramic and metal do not really bond chemically. So how did you accomplish this?

Ceramic and metal not only do not bond, they actually expand at different rates when the temperature changes, which also makes producing a composite difficult. Working in a number of test series, we examined the composite material in terms of its composition, its structure and its functional properties. We were ultimately able to bind the ceramic and platinum particles to one another and create a dense composite free of defects. Without interdisciplinary cooperation and close collaboration involving a number of colleagues and departments, the development of the CerMet material would never have been possible.

What were the material and technical challenges in developing CerMet?

In order to be able insert conductive metal directly into ceramic during the production process, it was necessary to calibrate a number of different material-specific parameters. So not only did the nature and composition of the metal and ceramic powder have to be optimized, but the right additive had to be introduced in the right concentration. By conducting systematic studies, we not only determined the precise amounts of the individual components, we also developed the appropriate production processes.

New applications for use in minimally invasive surgery with the CerMet technology: