A team working in a new area called soft robotics at the Johns Hopkins University in Baltimore, MD, is developing tiny, self-folding devices that could be used to perform biopsies or precisely deliver drugs inside living tissue. The researchers report their work in the journal ACS Applied Materials & Interfaces.
The team led by Prof. David Gracias of the Department of Materials Science and Engineering at Johns Hopkins, made self-folding microgrippers that they believe could someday allow surgeons to perform minimally invasive biopsies or deliver drugs to precise locations inside the body via remote control.
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. Hydrogel deformed well, but was not stiff enough to grip and hold anything. However, after running several experiments and computer models, the team discovered that combining the soft, swellable hydrogel with a stiff, biodegradable polymer that does not swell, could make a self-folding microgripper that can wrap around cells and remove them from surrounding tissue.
The team took the prototype further by embedding iron nanoparticles in the stiffened hydrogel structure so it could be remotely controlled and moved around using a non-attached magnetic probe. The researchers say their new material could give surgeons the ability to remotely direct where biopsies are taken.
This development will give doctors the ability to treat remote infections effectively without touching other healthy tissues.