Now, 3D robot that can swim, crawl and climb

In a breakthrough, scientists have developed a three-dimensional (3D) robot that can move forward or backward in a wave-like motion, allowing it to climb over obstacles, swim or crawl through unstable terrain like sand, grass and gravel.
The first single actuator wave-like robot (SAW) developed by researchers from Ben-Gurion University of the Negev (BGU) in Israel has applications in medicine, security and search and rescue.
SAW can climb over obstacles or crawl through unstable terrain like sand, grass and gravel, reaching a top speed of 57 centimetres per second, five times faster than similar robots, researchers said.
The 3D-printed robot can move forward or backward in a wave-like motion, moving much like a worm would in a perpendicular wave, they said.

Its minimalistic mechanical design produces an advancing sine wave with a large amplitude, using only a single motor with no internal straight spine.
"Researchers all over the world have been trying to create a wave movement for 90 years. We succeeded by finding a simple, unique solution that enables the robot to be built in different sizes for different purposes," said David Zarrouk from BGU.

"For example, it can be scaled up for search and rescue and maintenance, or miniaturised to a diameter of one centimetre or less to travel within the human body for medical purposes, such as imaging and biopsies of the digestive system," he said.

The robot's innovative wave movement also enables it to climb through tunnels at a rate of eight centimeters per second when touching both sides. A waterproof version can swim at six centimetres per second, researchers said.
By adding spiny traction enhancers to each link, researchers were able to propel the robot 13 per cent faster than its own wave speed.
Zarrouk, who has been developing robots with a minimalistic and high-performance approach for many years, claims that SAW is easy to manufacture, strong, reliable, and energy efficient, which enables long-distance travel.
"The robot requires barely any maintenance, which is very unusual for an almost completely 3D-printed prototype that is this dynamic," said Zarrouk.

"I believe it will be useful for traveling through the intestine for imaging and biopsies, and for infiltrating problematic, complex security areas, such as tunnels, destroyed buildings and pipes," he said.
The findings were published in the journal Bioinspiration & Biomimetics.