Researchers at the University of Illinois have developed a ‘sucker’ to pick up and transfer thin cell or tissue sheets that are intended for therapeutic purposes, such as wound healing or tissue grafting. Inspired by octopus suckers, the device can gently manipulate the delicate sheets without causing damage, and uses heating and a temperature-responsive hydrogel to create suction between the sucker and the sheet.
“For the last few decades, cell or tissue sheets have been increasingly used to treat injured or diseased tissues. A crucial aspect of tissue transplantation surgery, such as corneal tissue transplantation surgery, is surgical gripping and safe transplantation of soft tissues,” said Hyunjoon Kong, a researcher involved in the study. “However, handling these living substances remains a grand challenge because they are fragile and easily crumple when picking them up from the culture media.”
Thin films are hard to handle manually.
The device is inspired by the suckers present on the octopus, which can pick up wet and slippery materials with ease. Octopus suckers use muscle manipulation to exert suction, without sticky adhesives. In the new device the ‘sucker’ applies heat to a temperature responsive hydrogel layer, causing it to shrink a little, and then once pressed onto the thin sheet the heat stops, causing the hydrogel to expand again.
This expansion creates a low-pressure area of suction between the hydrogel and the cell sheet, allowing the device to then lift the cell sheet without causing any damage. Once the sucker is moved into position, the heat can be applied again, causing the hydrogel to gently release the thin film.
“During surgery, surgeons must minimize the risk of damage to soft tissues and transplant quickly, without contamination,” said Kong. “Also, transfer of ultrathin materials without wrinkle or damage is another crucial aspect.”
Other applications include moving delicate sheets of electronic components for wearable biosensors. The next steps will involve integrating sensors into the device so that it can measure the forces being applied to the films, to ensure that they maintain their integrity and don’t get damaged.
See a University of Illinois video about the device below:
Study in Science Advances: Electrothermal soft manipulator enabling safe transport and handling of thin cell/tissue sheets and bioelectronic devices