Bionics exercises great fascination for many different reasons. It promises 'adapted', ecologically compatible solutions for social problems. An important contribution towards implementing this promise consists in working out the 'rational core' of this promise, on the one hand, and on the other hand in 'demystifying' it as well. It must be made clear that bionic solutions, just like other technical solutions, must be subjected to a technical evaluation process. This process must clarify whether and to what extent the above-mentioned promise can be kept.