Hi, my name is Pin-Sung Ku, a phd student from the Hybrid Body Lab at Cornell University,
and today I’ll be presenting our work, titled, Patch-O: Deformable Woven Patches for On-body actuation.
Patch-O exploits a woven patch form factor to enable diverse movement-based interactions.
The Patch-O interfaces are uniquely detachable and relocatable soft actuation units that
can be sewn or attached to clothing or skin.
This work is inspired by researchers that have been pushing the boundaries of expressive
and interactive textile interfaces.
However, there is, in general, a tradeoff between two directions of practice.
One end of the work fabricates specially designed garments for a single actuation.
Through a longer period of fabrication, it can achieve a conformable slim form factor.
On the other hand, building detachable actuation parts can realize faster fabrication and support
actuation effects more diversely, but the bonding between the fabric and the typically
non-textile device often brings undesired rigidity and thickness.
In this work, we seek to find a balance between the two trends, where we came across an under
explored textile practice, woven patches.
We extend the concept of patching from mending and repairing into a new role: textile deformation.
We created morphing woven patches that are flexible and conform to the clothing or human
body.
The versatile functions and detachability the patches provide are also ideal for quick
prototyping or testing.
Patch-O is built upon several critical design choices we referred to in previous literature,
including the fabrication method, the actuation mechanism, and the materials.
The first critical design choice is the fabrication methods.
Techniques such as Digital embroidery or 3D printing construct circuits with conductive
material over the base fabric at a surface-level.
While textile construction approaches such as weaving and knitting allow the material
integration to take place at a structural level.
Among the options, we choose weaving because of its intersecting structure that makes embedding
material inherently simple.
In terms of actuation mechanisms, we’ve seen works utilize mechanical actuations with
motors, pneumatic actuations with expandable inflation channels, and also biological mechanisms
that utilize the natural response of living organisms.
However, these approaches are either limited by the size, mobility, or are difficult to program the control.
In contrast, we found Shape-memory alloy (SMA) to be especially promising for on-body deformations
due to its energy efficiency and flexibility.
Different forms of SMA products such as a spring or a wire can be integrated into various
form factors to achieve diverse interactions.
Unlike previous work that often targets a single SMA actuation mechanism, we successfully
integrated three types of SMA products to the woven patches to enable a wide range of morphing effects.
Next, I would like to talk about the implementation of the Patch-O system.
We implemented three basic actuation primitives: bending, expanding, and shrinking.
Each primitive was built upon the choice of SMA actuators and customized woven substrates
For each primitive, we also identified the aggregation parameters to extend the actuation library of Patch-O.
First we have the bending mechanism.
We used the SMA wire for contraction, and wove a stiffer fabric on the two sides to
constrain the deformation while anchoring the SMA.
The central region woven with silk is softer, and the section of SMA floats either above
or below the softer region.
Since the stiffer regions on the sides restrain the SMA, the shrinkage concentrates at the
flexible region in the middle and pulls the softer part of the fabric on both ends.
The patch would then be bent in the direction curving toward the SMA wire.
To create more complex deformations, one can weave multiple softer regions to divide the
patch into sections in the one-dimensional or two-dimensional space and control the bending
direction between each section by manipulating the SMA wire integration.
The second mechanism is expanding.
In reverse to the bending mechanism, the shape memory effect of the SMA wire can be used
to expand the fabric from a flat 2D shape to a 3D structure.
We adopted the double cloth weaving technique to create an expandable structure, where the
expansion happens at the bent joint.
When actuated, the SMA wire would tend to recover from the bent status back to a straight
line, which expands and opens the folded double cloth structure.
In addition to the open/close patch design, some other representative designs of the expanding
patch include the tube shape and the X-shape, where the top and bottom layers are connected
on different locations.
Finally, we have the shrinking mechanism that creates a much more prominent shrinkage across
the whole fabric surface by leveraging the SMA spring.
We set up supplementary warps with copper wires.
A tiny ring structure was designed to trap the SMA spring for solid electrical connections,
as shown in the figure.
One can integrate multiple SMA springs to increase the pulling force.
Adding warps of copper wire can also allow more segment controls of the SMA spring.
With all the designs we identified in the implementation, we conducted a workshop study
to gauge the feasibility of creating personalized morphing patches, and to probe perceptions
towards the patch form factor.
The first study result is Ren’s project: an expanding patch for opening a third eye.
Ren is a textiles artist with 17 years of weaving experience.
She expressed her love of integrating emotional elements into her textile practice, aiming
for the moment when humor and vulnerability intersect.
The patch is woven in a one margin double weave, with the bent joint of SMA connecting
the two layers, referencing our expanding patch design.
After weaving the double cloth structure, she then interwove the eye pattern with black yarn.
Next we have Kendall’s project: wave-bending patches as dynamic fringes.
Kendall is a textiles studio assistant with 5 years of weaving experience.
They integrate abstract, colorful patterns into the weaving practice.
Kendall chose the “Bending" primitive and implemented the wave shape aggregation method.
Besides, they customized their patch through tapestry weaving with colored cotton yarns
for aesthetic purposes.
The third project is done by Blair, a PhD student in apparel design with one year of
weaving experience.
Blair prioritizes function over aesthetics, and a function she found missing from her
clothing was the self-fitting capabilities when needed.
She selected the "Shrinking" primitive for the strong force it can provide.
As shown in the video, she applied the patch behind the back of the shirt, which could
create a better form-fitting silhouette for professional contexts.
Last but not least, we have Alex’s Project: A Tubular Expansion Patch for Surprising Outcomes.
Alex is an Engineering and Design undergraduate senior with 1.5 months experience in weaving.
She was interested in designs that were “extreme,” “absurd,” so that she could be “surprised
by the outcome.”
She attached the patch to a mask which would open and close like a mouth.
She also tried locations such as under the upper part of her hair, for the expansion
in volume, and to her jeans as a belt hoop that could expand to make it easier to loop
in a belt.
Alex experimented playfully with various patch deployment locations until reaching the ideal
setup for each location.
During the workshop study, we observed that: The temporary and quick yet sturdy reattachment
of the patch interface allowed playful experimentation with movement on diverse locations.
The participants also found the gradual shape change afforded by SMAs to be surprising,
but to resemble deformations typically seen in existing garments.
While some participants prioritized the effective aesthetic expression of their patches, others
designed for resolving practical clothing issues which could benefit from a moving patch.
Lastly, our participants ranged from beginner to expert weavers.
For discussion, we acknowledge that the actual on-cloth deformation is affected by
various factors ranging from the tension of the body, deployment angle, to fabric structure.
A more comprehensive test with exhaustive conditions is required to understand the exact
on-cloth performance of Patch-O.
To support actuating multiple patches, we plan to build a custom PCB board to address
multiple powering requirements and realize an untethered system design.
In our workshop study, we observed that the most time-consuming aspect of the fabrication process is weaving the patches.
While the woven interfaces can also be fabricated through digital Jacquard looms for scalability and speed,
this does trade off the real-time, creative experimentation offered by hand weaving.
However, it could serve as an option for scaling up a finalized design for broader usage.
Above all, I would like to conclude the project with the following highlights.
This project is supported by the national science foundation.
Thank you for listening.