Partially living 3D-printed bio-bots developed

Scientists have 3D printed small, soft bio-bots with living tissues that can not only walk and swim, but also have the ability to age as well as heal if there is an injury.

Researchers at University of Illinois in the US made a soft 3D printed scaffold measuring a centimetre or two in length and seeded it with muscle cells.

The cells then self-organised to form functional tissues that make the bio-bots move.

"These machines are now viewed as partially living, with the ability to form, the ability to age and the ability to heal if there is an injury," said Taher Saif from Illinois.

"Now that we have got them working, we are beginning to look back and try to understand how the cells organise themselves and what language they use to communicate. This is the developmental biology of living machines," he said.

"As engineers, we usually build with materials like wood, steel or silicon. Our focus here is to forward-engineer biological or cell-based systems," said Rashid Bashir, head of the bioengineering department at the University of Illinois. "The design is inspired by the muscle-tendon-bone complex found in nature. There is a skeleton or backbone, but made out of soft polymers similar to the ones used in contact lenses, so it can bend instead of needing joints like the body does," he said.

Bashir's group developed multiple designs to make bio-bots walk in certain directions and to control their motion with light or electrical currents. They form a single muscle unit that contracts to beat a tail, propelling the bio-bot through liquid. "They align themselves in a direction where the tail of the swimmer can be bent most. Which is exactly what we wanted, although we did not pattern or direct them to do it," said

Saif. "The objective is not to make a walker and a swimmer, but to lay the scientific foundation so we have principles for building biological machines in the future," Saif added.