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.
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
First transcatheter implant for diastolic heart failure successful
16.11.2017 | The Ohio State University Wexner Medical Center
Theranostic nanoparticles for tracking and monitoring disease state
13.11.2017 | SLAS (Society for Laboratory Automation and Screening)
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences