Key technologies such as micro- and nano-technology are now firmly established on the medical technology market. The technologies are essential to the creation of smart, miniaturised medical devices.
Micro-technology is already enabling the production of wide-ranging mobile diagnostic, monitoring and therapy systems today. And micro-electronic implants are also playing an ever greater role. Smart implants combine therapy and diagnostics to provide so-called “theranostics” in a single system. They integrate sensors, actuators and signal processing. State-of-the-art micro- and nano-technology methods help to hermetically secure the tiny components of the implants, so as to attain long-term stability and safety.
Small, but wow
“The life sciences industry is seeing rising demand for miniaturisation, micro-structuring and integration of optical and electrical functions in low-cost components,” affirms Peter Kirkegaard, CEO of Swiss company IMT Masken und Teilungen AG. IMT is responding to that demand by applying manufacturing technologies from the semiconductor industry. The company makes micro-channels, through-holes, electrodes, optical and electrical coatings, optical waveguides and lattices based on glass. The smallest structures are as little as 150 nanometres in size (by comparison: the smallest bacteria are about 300 nanometres long). Their applications include lab-on-a-chip systems.
The Erfurt-based CiS research institute has developed a special miniaturised, silicon-integrated sensor for wearables. The multi-spectral photoplethysmographic sensor detects the reflections of emitted infrared light beams. From this, measurement data for pulse rate, arterial oxygen saturation, heart rate variability or respiratory rate can be derived, as well as information on hardening of the arteries and signs of rising or falling blood pressure. The sensors are placed in the outer auditory canal. They use up to four LEDs of differing wavelengths to additionally record data from various tissue depths, and to detect and eliminate motion artefacts.
Robots in the bloodstream
Particularly striking examples of ever-advancing miniaturisation are nano-robots in the bloodstream which autonomously perform surgical procedures. The Max Planck Institute (MPI) for Intelligent Systems in Stuttgart has developed concepts in this field using two different micro-floats. The first is a type of clamshell which moves by opening and closing; the second is a screw which advances by rotating. It is just 100 nanometres in diameter, and 400 nanometres long. A rotating magnetic field applied from the outside sets the miniature screw in motion. The special floats are 3D-printed. All materials used, such as polydimethylsiloxane (PDMS), are biocompatible and non-harmful to the body. The researchers envisage that the nano-robots will one day deliver therapeutic agents directly into a tumour, for example. “Theoretically, based on the size of our structure, it is even conceivable that it could be used inside cells,” explains Peer Fischer, head of the Micro-, Nano- and Molecular Systems working group at the MPI for Intelligent Systems. In any case, the tiny devices will help to advance the use of minimally invasive procedures, improving their efficacy and shortening the time they take. It is likely to be a number of years yet before this science-fiction becomes reality, however.