NEWS & TECHNOLOGY HAPTICS
Origami unfolds as force feedback haptics
By Julien Happich
Researchers from EPFL’s
NCCR Robotics lab have
designed a novel form of
force feedback haptics based on a
folding origami structure which can
be flattened into a highly wearable
card when not in use.
Still under development to be
commercialized by spin-off startup
Foldaway Haptics, the so-called
Foldaway device leverages well
established planar manufacturing
techniques such as lamination and
printed-circuit microelectro-mechanical
systems (PC-MEMS) to
offer unobtrusive and cost-effective
force feedback haptics. Two
3D model of the delta mechanism (left). Each leg is connected to an axis of rotation driven by
a direct-current motor through bevel gears. A Hall effect sensor measures the orientation of a
diametrically magnetized magnet connected to the axis of rotation. The hand-held versions of
the push-button (right) is built around the same sensors and actuators but sports a different
spatial arrangement.
device implementations are described in the Nature Machine
Intelligence journal in a paper titled “A portable three-degreesof
freedom force feedback origami robot for human–robot interactions”,
a delta version and a push-button version. Both could
become low-cost PC peripherals, akin to a mouse. Integrated
into the touch-pad area of a laptop, the Foldaway buttons could
enable users to feel the textures or the stiffness of objects as
seen on screen or in virtual reality environments, accurately rendering
touch sensations during interactions with virtual objects.
The delta Foldaway haptics allows joystick manipulation with
3 degrees of freedom.
For the push-button version, three individual micro-motors
are linked via bevelled gears to a three-legged flat structure.
Each actuator imparts movements, forces and vibrations along
a distinct direction slotted into the base, folding the legs along
a pre-defined pattern of joints to take a 3D, button-like shape.
The upper tip of this moving origami mechanism is the actual
user interface, transmitting sensations and force feedback
to the user’s finger to reproduce the physical interaction with
objects or forms. Hall effect sensors keep track of the tip’s
movements so the whole system can be controlled via a retrofeedback
loop.
The delta version is aimed at larger movements, to be used
like a joystick where users actually grab the tip and interact with
it in all directions. With a footprint under 100x100mm and just
about 30mm thick (to accommodate the DC micro-motors),
the devices were successfully tested to navigate an atlas of the
human anatomy, giving users different sensations upon passing
on various organs based on their known stiffness (lungs, bones,
heartbeat etc..). As a virtual reality joystick, the Foldaway gave
users the sensation of grasping virtual objects and perceiving
their stiffness, modulating the force generated when the interface
was pressed.
Another use case described in the paper is a control interface
for drones, increasing the pilot’s awareness on drone’s
behaviour and of the effects of wind or other environmental
factors.
The hand-held version of the push-button used to provide
haptic force feedback in a virtual reality environment.
6 News January 2020 @eeNewsEurope www.eenewseurope.com
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