Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Like a snail through the intestinal canal

21.09.2006
The medical device currently used for intestinal research, the colonsope, causes patients great discomfort. At TU Delft, an alternative method has been developed, inspired by the way in which snails move. On September 18, researcher Dimitra Dodou received her PhD degree from TU Delft based on this research subject.

The intestines are an extremely difficult area to navigate through with a medical device. Yet, many people need to have intestinal examinations done to determine if, for example, they have intestinal cancer. The medical device currently used for this is the colonscope, a long, thin and flexible tube that causes patients great discomfort and pain.

For this reason, researchers have been trying to develop alternative medical devices, such as, for example, a small robot that moves independently through the intestinal tract. There is a layer of slime, called mucus, on the inside of the large intestine (colon). The robots, as they move forward under their own power, ignore this layer of mucus and try, if possible, to suck or grab on to the intestinal wall, which results in the walls being stretched and the patient feeling pain and discomfort.

A better method, according to TU Delft researcher Dimitra Dodou, is in fact to use this layer of mucus and allow the robot to imitate the forward movement of a snail. A snail leaves a trail of slime behind it on the ground. This slimy material works simultaneously as a lubricant for gliding on and as a glue which the slug can grip hold of.

An intestinal robot should also have a similar layer to use. To achieve this, an adhesive layer is added to the mucus-like properties, which allows the device to be stuck to the layer of mucus. The ability to be attached to a surface covered with lubricant is a great technological challenge, because most adhesives normally only work on 'clean' surfaces. The researchers discovered a group of polymers, so-called muco-adhesives, that are suitable for this. Dodou used a pig's intestine to evaluate how this material worked. Her findings revealed that muco-adhesives in the form of films provided by far the highest degree of friction.

Despite this, there is nevertheless no possibility of movement. A snail uses the exertions of pressure to change the characteristics of the middle layer, and thus lower the degree of friction, in order to move. In the intestine, however, pressure cannot be exerted, because this would cause the intestine to become deformed. The solution then is found in using smaller and larger surfaces that slide over each other. If a large surface coated with muco-adhesive remains still, and a relatively small surface coated with muco-adhesive begins moving in relation to the larger surface, the smaller surface has less freedom of movement. One by one the small 'hands' of the robot move forward. After this, the entire robot can be slide forward incrementally, whereupon the process of small surfaces shifting begins anew.

Additional experiments found that it is not only the size of the film surfaces, but also their shapes, which influence the degree of friction generated. It's remarkable that the degree of friction increases when the surface size decreases, as a result of holes being made in the structure of the film. It is therefore possible to influence the degree of friction by creating holes in the muco-adhesive or indeed by closing the holes.

Moreover, by selecting different shapes, which owing to their compact size can achieve high degrees of friction, the device can be made smaller.

The researchers are currently building a prototype that will be tested in living pigs. We must however wait a while longer until a fully developed medical device is available.

Maarten van der Sanden | alfa
Further information:
http://www.delta.tudelft.nl/images/slakken.wmv

More articles from Medical Engineering:

nachricht New imaging technique able to watch molecular dynamics of neurodegenerative diseases
14.07.2017 | The Optical Society

nachricht Quick test finds signs of sepsis in a single drop of blood
03.07.2017 | University of Illinois at Urbana-Champaign

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>