Nanotube-coated tissue-paper sensor can track eyeball movement

By Warren Miller,
contributing writer

Wearable technology seemingly gets smaller and more
inconspicuous with each passing day, but the latest breakthrough will surprise
even the most stoic tech savant. A team of engineers at the University of
Washington has constructed a wearable sensor out of tissue
paper
, and you can not only blow your nose into it, but you can also use
it to detect barely perceptible movements such as the blink of an eye or the
beat of a heart.

In a paper published in last month’s issue of
the scientific journal Advanced Materials Technologies
, the UW team
illustrates that when an ordinary piece of tissue paper is soaked in a solution
of carbon nanotube-laced water and then torn into pieces, the broken fibers of
the paper take on sensory properties. The little strips of tissue paper can
detect subtle movements of the human eye and finger, making them potentially
applicable in a variety of diverse fields such as healthcare and gaming.

“When tissue paper coated with carbon nanotubes is stretched
by a designed length, the cellulose fibers coated with nanotubes are fractured
and reoriented to form crossbar junctions near a crack,” Jinyuan Zhang, lead
author on the paper, told Digital Trends. “The junctions
create highly sensitive resistive and capacitive sensors. The resistive sensors
can be used to measure strain, force, and pressure. The capacitive sensors can
be used to measure force, pressure, and non-contact displacement.” According to
Zhang, the sensors can also be used to measure heartbeats, finger movement,
eyeball movement, and other human behavior.

Wearable_Sensor

The wearable sensor is
capable of detecting a person’s pulse and the blink of an eye. Image source:
University of Washington.

The paper sensors can be smaller than an adhesive bandage and
are lightweight, flexible, and more cost-effective than their more cumbersome
predecessors. When placed on different parts of the body, they have many
different potential applications. A user could wear one on his or her glasses,
for instance, in order to respond to the movement of their eye(s). Imagine that you’re playing a video game without using your hands to manipulate the
controller — you
can control your avatar with the wink of an eye, literally. The sensors also
have huge future potential in medicine, such as possibly studying the extent of
brain damage by tracking a patient’s arm and/or leg movement.

The use of such a common product like tissue paper as the
“platform” for a complex sensor brings up many questions. What other common
household items, when treated with an exotic substance like carbon nanotubes,
turns into a useful, super-powered “mutant?” Could regular cotton fibers be
treated with an exotic substance to make them produce power, deflect dirt, kill
microbes, or tone your muscles? The possible combinations of normal items and
“mutagen” exotic substances seem virtually limitless. What could be next?

The UW team is looking into commercial applications for
their technology as we speak and have a patent on file as of December 2017. Although
they’re still in the early stages, it might not be long until you see people
walking around with pieces of tissue paper stuck to their pants leg — on purpose.