Tech Briefs Magazine - December 2023 - MD-15

namic range of responses. A little fuel
and some high-frequency
sparking
makes the robot skitter across the
ground. Add a bit more fuel and less
sparking and the robot will slow down
and hop. Crank the fuel all the way up
and give it one good spark and the robot
will leap 60 cm in the air, roughly 20
times its body length, according to
Aubin.
" To do all those multi-gait movements is
something that you don't typically see with
robots at this scale, " Aubin said. " They're
either crawlers or jumpers, but not both. "
The researchers envision stringing together
even more actuators in parallel
arrays so they can produce both very
fine and very forceful articulations on
the macro scale. The team also plans to
continue work on creating an untethered
version. That goal will require a
shift from a gaseous fuel to a liquid fuel
that the robot can carry on board, along
with smaller electronics.
" Everybody points to these insect-scale
robots as being things that could be
used for search and rescue, exploration,
environmental monitoring, surveillance,
navigation in austere environments, "
Aubin said. " We think that the performance
increases that we've given this
robot using these fuels bring us closer to
reality where that's actually possible. " .
For more information, contact Becka
Bowyer at rpb224@cornell.edu; 607220-4185.
Building
More Dexterous Robots
A finger-shaped sensor could enable a robot to grasp and manipulate objects in multiple ways.
Massachusetts Institute of Technology, Cambridge, MA
I
magine grasping a heavy object, like a
pipe wrench, with one hand. You
would likely grab the wrench using your
entire fingers, not just your fingertips.
Sensory receptors in your skin, which
run along the entire length of each finger,
would send information to your
brain about the tool you are grasping.
In a robotic hand, tactile sensors that
use cameras to obtain information about
grasped objects are small and flat, so
they are often located in the fingertips.
These robots, in turn, use only their fingertips
to grasp objects, typically with a
pinching motion. This limits the manipulation
tasks they can perform.
MIT researchers have developed a
camera-based touch sensor that is long,
curved, and shaped like a human finger.
Their device provides high-resolution
tactile sensing over a large area. The
sensor, called the GelSight Svelte, uses
two mirrors to reflect and refract light so
that one camera, located in the base of
the sensor, can see along the entire finger's
length.
In addition, the researchers built the
finger-shaped sensor with a flexible
backbone. By measuring how the backbone
bends when the finger touches an
object, they can estimate the force being
placed on the sensor.
They used GelSight Svelte sensors to
produce a robotic hand that was able to
grasp a heavy object like a human would,
using the entire sensing area of all three
of its fingers. The hand could also perform
the same pinch grasps common to
traditional robotic grippers.
Motion Design, December 2023
Researchers have developed a camera-based touch sensor that is long, curved, and shaped like a human
finger. Their device, which provides high-resolution tactile sensing over a large area, could enable a robotic
hand to perform multiple types of grasps. (Image: Courtesy of the researchers)
" Because our new sensor is human finger-shaped,
we can use it to do different
types of grasps for different tasks, instead of
using pinch grasps for everything. There's
only so much you can do with a parallel jaw
gripper. Our sensor really opens up some
new possibilities on different manipulation
tasks we could do with robots, " said Alan
(Jialiang) Zhao, a mechanical engineering
graduate student and lead author of a
paper on GelSight Svelte.
Once they had perfected the design,
the researchers tested the GelSight
Svelte by pressing objects, like a screw, to
different locations on the sensor to
check image clarity and see how well it
could determine the shape of the object.
They also used three sensors to build
a GelSight Svelte hand that can perform
multiple grasps, including a pinch grasp,
lateral pinch grasp, and a power grasp
that uses the entire sensing area of the
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Tech Briefs Magazine - December 2023

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