'Soft micro-robots' could do biopsies, deliver drugs

Date: Feb-06-2015 At The Johns Hopkins University in Baltimore, MD, a team working in a new area

called soft robotics is developing tiny, self-folding devices that could one day be used

to perform biopsies or precisely deliver drugs inside living tissue.

Star-shaped microgrippers could one day help surgeons perform minimally invasive biopsies.
Image credit: American Chemical Society

Soft robotics is a new area of research that is attracting interest from many fields.

It uses soft and deformable structures to enable robotic systems to work in uncertain and

dynamic environments; for example, to grasp and manipulate unknown objects, move about in

rough terrains, and - as in the case of this new study - deal with living cells inside

human bodies.

Another exciting area that is applying soft materials to robotic systems is

more visionary research, such as self-repairing, growing and self-replicating robots.

However, as far as medical applications are concerned, soft robotics is still very

new, so much of current research concerns itself with testing new materials and looking

at potential applications rather than producing devices that are ready for clinical

trials.

The team behind the new study made and tested a new material by using it to make

"self-folding microgrippers" that they believe could one day allow surgeons to perform

minimally invasive biopsies or deliver drugs to precise locations inside the body via

remote control.

The researchers report their work in the journal ACS Applied Materials &

Interfaces.

Microgrippers that can wrap around and remove cells from tissue

The self-folding microgrippers - which look like sea stars with six arms that can fold

into themselves - are made of a hydrogel that swells and shrinks in response to changes

in temperature, acidity and light.

At first, the researchers - led by Prof. David Gracias of the Department of

Materials Science and Engineering at Johns Hopkins - found that while the hydrogel

deformed well, it was not stiff enough to grip and hold anything.

But after running several experiments and computer models, the team found if they

combined the soft, swellable hydrogel with a stiff, biodegradable polymer that does not

swell, they could make a self-folding, microgripper that can wrap around cells and remove

them from surrounding tissue.

In a further step, the team embedded iron nanoparticles in the stiffened

hydrogel structure, so it could be remotely controlled and moved around using a non-attached magnetic probe.

The advantage of such a device is that it does not require wires to power it and make

it move, so it can stay small and nimble.

The following video shows how the microgrippers work:

New material could give surgeons ability to remotely control biopsies

The researchers say their new material could be used in microassembly or

microengineering of soft or biological parts, or to give surgeons the ability to remotely

direct where biopsies are taken.

Prof. Gracias says the microgrippers show what can be done with these new

materials, and their work opens the way to a range of biodegradable, miniaturized

surgical tools that can safely dissolve in the body.

Funds for the study came from the National Science Foundation and the National

Institutes of Health.

The study is a good example of new robotic methods that help keep surgical

interventions as minimally invasive as possible. The less that surrounding tissue is disturbed in sampling and removing tumors, the

lower the risk of complications and the faster the patient recovers.

Another remarkable example of this is a study that Medical News Today reported in

December 2014, where researchers have pioneered a minimally invasive, robot-assisted

procedure for treating tumors deep inside the neck or head

that were previously inoperable.

Written by Catharine Paddock PhD

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.