Tech Briefs Magazine - October 2022 - MD-17

A gripper is used to lift a jumper and break a circuit on an electronic breadboard, turning off an LED. (Image: Courtesy of the Preston Innovation Laboratory)
types of actuation and materials, " Preston
said. " The spider falls into this line of inquiry.
It's something that hasn't been used
before but has a lot of potential. "
Unlike people and other mammals
that move their limbs by synchronizing
opposing muscles, spiders use hydraulics.
A chamber near their heads contracts
to send blood to limbs, forcing
them to extend. When the pressure is
relieved, the legs contract.
The cadavers Preston's lab pressed
into service were wolf spiders, and testing
showed they were reliably able to
lift more than 130 percent of their
own body weight, and sometimes much
more. They had the grippers manipulate
a circuit board, move objects, and even
lift another spider.
Internal valves in the spiders' hydraulic
chamber, or prosoma, allow them
to control each leg individually, and
that will also be the subject of future
research, Preston said. " The dead spider
isn't controlling these valves, " he
said. " They're all open. That worked
out in our favor in this study, because it
allowed us to control all the legs at the
same time. "
Setting up a spider gripper was fairly
simple. Yap tapped into the prosoma
chamber with a needle, attaching it
with a dab of superglue. The other
end of the needle was connected to
one of the lab's test rigs or a handheld
syringe, which delivered a minute
amount of air to activate the legs almost
instantly.
The lab ran one ex-spider through
1,000 open-close cycles to see how well
its limbs held up, and found it to be
fairly robust. " It starts to experience
some wear and tear as we get close to
1,000 cycles, " Preston said. " We think
that's related to issues with dehydration
of the joints. We think we can overcome
that by applying polymeric coatings. "
Preston said a few necrobotic applications
have occurred to him. " There are a
lot of pick-and-place tasks we could look
into, repetitive tasks like sorting or moving
objects around at these small scales,
and maybe even things like assembly of
microelectronics, " he said.
For more information, contact Mike
Williams at mikewilliams@rice.edu; 713348-6728.
A
Manta Ray-Inspired Bio-Syncretic Robot
The robot is actuated by cultured skeletal muscle tissue and controlled by circular distributed
multiple electrodes.
Beijing Institute of Technology, China
I
nspired by manta rays, a team from the
State Key Laboratory of Robotics at the
Shenyang Institute of Automation,
Chinese Academy of Sciences, has developed
a bionic swimming robot that is
actuated by cultured skeletal muscle tissue
and controlled by circular distributed
multiple electrodes (CDME). The
robot can be efficiently propelled by
only one muscle tissue.
Biomimetics is one of the most important
robotic research methods which
can improve the kinematic performance
of robots by imitating the structure and
behavior of natural organisms. The
bio-syncretic robot, which takes natural
biological materials as the core element,
is the further development of bionics.
Motion Design, October 2022
Some living cells have been used to realize
some functions of robots, including
sensing, control, actuation, etc., among
which actuation as a key factor to determine
its performance, is related to the
overall performance of robots. However,
innovative propulsion and control methods
are needed to further develop the
controllable motion performance of
bio-syncretic robots. To solve this problem,
researchers proposed a dynamic
control method based on CDME.
The team found that the electric field
generated by CDME was less harmful to
the culture medium and cells than conventional
electrodes. Using this method,
the direction of the electric field generated
by the electrode could be dynamically
controlled, keeping it parallel to the
driving tissue of the robot in real-time,
thus ensuring stable control of the robot.
First, the team designed the robot
skeleton based on the manta ray's
structure and used polydimethylsiloxane
(PDMS) as the main material for
the structure. At the same time, to facilitate
the assembly of the driving tissue
and the robot structure, the researchers
chose the ring-shaped tissue made
by myoblasts as the drive unit of the
robot.
In addition, to obtain the circular
muscle tissues with effective contractility,
a rotational electric stimulation from
the CDME has been used to realize uniform
induction of the myoblasts to dif17

Tech Briefs Magazine - October 2022

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