A 3D-printed smart gel that walks underwater, moves objects

New technology has biomedical, soft robot and other applications.

A human-like 3D-printed smart gel walks underwater. Photo: Daehoon Han/Rutgers University-New Brunswick High Res
A human-like 3D-printed smart gel walks underwater. Photo: Daehoon Han/Rutgers University-New Brunswick High Res

Scientists at the Rutgers University have created a 3D-printed smart gel that moves and changes shape when activated by electricity. The gel can walks underwater and grabs objects and moves them.

Scientists reported that this watery creation could lead to soft robots that mimic sea animals like the octopus, which can walk underwater and bump into things without damaging them. It may also lead to artificial heart, stomach, and other muscles, along with devices for diagnosing diseases, detecting and delivering drugs and performing underwater inspections.

While printing the gel, scientists projected the light on a light-sensitive solution that becomes a gel. They then placed it in a saltwater solution or electrolyte and applied electricity to trigger motions such as walking forward, reversing course and grabbing and moving objects.

Howon Lee, senior author of a new study said, “The speed of the smart gel’s movement is controlled by changing its dimensions (thin is faster than thick), and the gel bends or changes shape depending on the strength of the salty water solution and electric field. The gel resembles muscles that contract because it’s made of soft material, has more than 70 percent water and responds to electrical stimulation.”

Scientists suggest that the gel could lead to soft robots that mimic sea animals like the octopus, which can walk underwater and bump into things without damaging them. It may also lead to artificial heart, stomach, and other muscles, along with devices for diagnosing diseases, detecting and delivering drugs and performing underwater inspections.”

Lee said, “This study demonstrates how our 3D-printing technique can expand the design, size, and versatility of this smart gel. Our microscale 3D-printing technique allowed us to create unprecedented motions.”

The study’s lead author is Daehoon Han, a doctoral student in mechanical and aerospace engineering in Rutgers’ School of Graduate Studies. Co-authors include former Rutgers undergraduate student Cindy Farino; Chen Yang, a doctoral student in mechanical and aerospace engineering; Tracy Scott, a former postdoc; Daniel Browe, a doctoral student in biomedical engineering; Joseph W. Freeman, an associate professor in the Department of Biomedical Engineering; and Wonjoon Choi, an associate professor in the School of Mechanical Engineering at Korea University in Seoul, Republic of Korea.

The study is published online in ACS Applied Materials & Interfaces.