Screen Printing - April/May 2017 - 8

Print tech

here comes the sun
Solar energy has long been a symbol of
progressive technology; these days, it's also
pushing the boundaries of fashion.
Kiersten Wones

echnology is not a mere tool, but rather one of aesthetics."
Dutch fashion designer Pauline van Dongen (paulinevandongen.nl) outlines this philosophy on her website, emphasizing the value and meaning that technology can bring to
fashion. "It's never about technology for technology's sake,"
the statement reads. Nevertheless, technology is what stands
out the most about van Dongen's apparel, blending distinctive
fashion statements with deliberate elements of convenience
and function.
You certainly wouldn't find styles like hers at Macy's. From
FysioPal - a top for improving posture that vibrates when the
wearer slouches - to Skynfeel - a bodysuit designed to maximize airtime for long jumpers - her designs are adventurous
and purposeful. Vigour is a cardigan that utilizes stretch sensors
to monitor upper body movements in geriatric patients; an accompanying app gives data to the wearer and his or her physical therapist on the patient's movements throughout the day.
Mesopic and Phototrope emit light to keep night runners safe.
Van Dongen's solar collection is a little closer to "everyday" wear. By integrating thin-film photovoltaic cells, her line
of jackets, dresses, and shirts allows the wearer to charge
their smartphones and other mobile devices via USB cable.
For example, the Solar Shirt prototype produces roughly
1 watt of electricity in bright sunlight - enough to charge a
phone for a few hours. Indoors, the shirt produces enough
wattage to keep a device charged. It can also store electricity
in a battery pack for later use, and it's washable.

collaboration is Key
The photovoltaic cell modules for the Solar Shirt were developed by Holst Centre (holstcentre.com), a research center dedicated to innovation in the field of flexible electronics. Margreet
de Kok, senior scientist, stresses the company's emphasis on
open collaboration: "Our partners - for instance, material suppliers and users - join forces in a pre-competitive state," she says.
It's a unique environment that encourages the flow of ideas.
For the Solar Shirt project, the van Dongen-Holst partnership
was a perfect example of how open collaboration can bring out
the best in all parties involved. "We develop technology, and to
the best of our expertise, we try to imagine what this technology
can bring in application," says de Kok. "But the design of it, we
realize, is not our cup of tea." That's where van Dongen came in.
The Solar Shirt serves as a showpiece to demonstrate both
the possibilities enabled by such collaboration as well as the
capabilities of thin-film electronics in fashion. De Kok says
8

screenprinting

pauline van
Dongen's designs
combine fashion
and function for an
avant-garde look
that comes in handy
when you're on the
go. this Solar Shirt
prototype was
designed with
photovoltaic cells
from Holst Centre.
images courtesy of
Holst Centre.

it's not quite ready for the commercial market yet - and that
wasn't the goal for this project - although new improvements
are being made every day.
One roadblock to commercial adoption is simply the cost of
production and materials. At Holst Centre, the modules begin as
a roll of thermoplastic polyurethane (TPU). A Dek Horizon 03i
roll-to-roll screen printer deposits DuPont 5025 silver conductor
on top; a number of components follow, including an isotropic
conductive adhesive from Henkel and the photovoltaic modules
themselves. Another layer of TPU is placed on top to seal everything together. The modules can then be laser- or die-cut in the
shape of the desired element and heat-pressed onto fabric. This
process lends itself perfectly to a mass manufacturing model,
but it's not without its complexities - ones that add up in price.
Holst Centre is working to improve the technology by making it more stretchable and flexible. The problem lies mainly
in the photovoltaic modules themselves, which to date aren't
stretchable. Rubber would be a preferable base material to
plastic for a number of reasons - it's more conformable and

http://www.paulinevandongen.nl http://www.paulinevandongen.nl http://www.holstcentre.com

Table of Contents for the Digital Edition of Screen Printing - April/May 2017