Researchers at the UCLA Henry Samueli School of Engineering and Applied Science have demonstrated for the first time an intrinsically stretchable polymer light-emitting device. |
Stretchable
electronics, an emerging class of modern electronic materials that can
bend and stretch, have the potential to be used in a wide range of
applications, including wearable electronics, “smart skins” and
minimally invasive biomedical devices that can move with the body.
Today’s
conventional inorganic electronic devices are brittle, and while they
have a certain flexibility achieved using ultrathin layers of inorganic
materials, these devices are either flexible, meaning they can be bent,
or they are stretchable, containing a discrete LED chip interconnected
with stretchable electrodes. But they lack “intrinsic stretchability,”
in which every part of the device is stretchable.
Now,
researchers at the UCLA Henry Samueli School of Engineering and Applied
Science have demonstrated for the first time an intrinsically
stretchable polymer light-emitting device. They developed a simple
process to fabricate the transparent devices using single-walled carbon
nanotube polymer composite electrodes. The interpenetrating networks of
nanotubes and the polymer matrix in the surface layer of the composites
lead to low sheet resistance, high transparency, high compliance and low
surface roughness.
The
metal-free devices can be linearly stretched up to 45% and the
composite electrodes can be reversibly stretched by up to 50% with little change in sheet resistance.
Because
the devices are fabricated by roll lamination of two composite
electrodes that sandwich an emissive polymer layer, they uniquely
combine mechanical robustness and the ability for large-strain
deformation, due to the shape-memory property of the composite
electrodes. This development will provide a new direction for the field
of stretchable electronics.
The research was supported by the National Science Foundation.
