Researchers have invented robotic droplet manipulators for cleaning dangerous liquids

According to a recent article in Materials Vision, the journal of the Royal Society of Chemistry, CSU researchers have succeeded in creating the first soft robotic gripper
capable of manipulating individual droplets.

The breakthrough is the product
of a collaboration between two different labs in the Department of Mechanical Engineering at the University of California.
This technology is achieved
by combining two application technologies, soft robotics and superhydrophobic coatings.

This soft robotic arm is made of inexpensive materials such as nylon fibers and tape
.
It is powered
by charged artificial muscles.
This combination can be used to produce lightweight, inexpensive pliers capable of doing delicate work, but at the same weight, it is 100 times
stronger than human muscle.

As a result, we are completely at odds with our cultural notions of what a robot is and what it can do
.

Traditional robots consist of
heavy, hard, expensive components.
This makes them unsuitable for certain tasks
.

Soft robots, on the other hand, can be light and provide a gentle touch that is difficult to achieve with conventional robots
.
They are much lighter in weight and cost a fraction
of the production cost of cemented carbide.

"A pair of pliers the size of my finger, including embedded artificial muscles, weighs one or two grams
.
And it's cheap — just a dollar or two," said Jiefeng Sun, a postdoctoral fellow at the Adaptive Robotics Laboratory in the Department of Mechanical Engineering and co-first author
of the paper.

The soft robot gripper handles a novel superhydrophobic coating that makes the droplet manipulator possible
.
This superhydrophobic coating is resistant to the wetting of almost all types of liquids, even in dynamic situations where the contact surface is tilted or
moved.
When applied to a flexible robotic arm, the coating enables it to interact with the droplet without breaking the surface tension of the droplet, so it can grab, transport, and release individual droplets as if they were flexible
solids.

The superhydrophobic coating for droplet manipulators was developed
by CSU associate professor Arun Kota (now at North Carolina State University) and Wei Wang, a postdoctoral fellow at the University of Tennessee.
Wang and Kota also contributed
to this article.

"This is a very good synergy between the two studies
.
Dr.
Kota is working on this very good coating, and we're working on this soft robot to manipulate droplets, so we thought it could be a good combination," said co-author Jianguo Zhao, associate professor of mechanical engineering and director of
the Adaptive Robotics Laboratory at California State University.

In the early stages of research, the team struggled to attract the attention
of journal editors.
The COVID-19 pandemic has provided an opportunity to point to their inventive potential
.

"Due to the pandemic, handling dangerous infectious material is a hot topic
.
So we added a blood manipulation experiment
after the first modification.
"It helped us get through the vetting process
in a way.
"

The combination of inexpensive materials and innovative capabilities has exciting applications
.
In the case of many liquid leaks, human cleanup can be dangerous
due to toxicity, risk of contagion, or other hazards in the environment.
These droplet manipulators are cheap enough to be used single-use, but have the ability to perform precise, non-destructive liquid cleaning jobs that no other robot has ever done
.

"This is a first, but it's also an example of a very unusual high-tech product that is not very expensive"
.