Mini Windmills Can Recharge Cell Phones
A UT Arlington research associate and electrical engineering
professor have designed a micro-windmill that generates wind energy and may
become an innovative solution to cell phone batteries constantly in need of
recharging and home energy generation where large windmills are not
preferred.
Smitha Rao and J.-C. Chiao designed and built the device that
is about 1.8 mm at its widest point. A single grain of rice could hold about 10
of these tiny windmills. Hundreds of the windmills could be embedded in a sleeve
for a cell phone. Wind, created by waving the cell phone in air or holding it up
to an open window on a windy day, would generate the electricity that could be
collected by the cell phone’s battery.
Rao’s works in micro-robotic
devices initially heightened a Taiwanese company’s interest in having Rao and
Chiao brainstorm over novel device designs and applications for the company’s
unique fabrication techniques, which are known in the semiconductor industry for
their reliability.
“The company was quite surprised with the
micro-windmill idea when we showed the demo video of working devices,” Rao says.
“It was something completely out of the blue for them and their
investors.”
Rao’s designs blend origami concepts into conventional
wafer-scale semiconductor device layouts so complex 3-D moveable mechanical
structures can be self-assembled from two-dimensional metal pieces utilizing
planar multilayer electroplating techniques that have been optimized by WinMEMS
Technologies Co., the Taiwanese fabrication foundry that took an initial
interest in Rao’s work.
“The micro-windmills work well because the metal
alloy is flexible and Smitha’s design follows minimalism for functionality,”
Chiao says.
WinMEMS became interested in the micro-electro mechanical
system research and started a relationship with UT Arlington. Company
representatives visited with the UT Arlington team several times in 2013 to
discuss collaboration.
An agreement has been established for UT Arlington
to hold the intellectual properties while WinMEMS explores the commercialization
opportunities. UT Arlington has applied for a provisional
patent.
Currently, WinMEMS has been showcasing UT Arlington’s works on
its website and in public presentations, which include the micro-windmills,
gears, inductors, pop-up switches and grippers. All of those parts are as tiny
as a fraction of the diameter of a human hair.
These inventions are
essential to build micro-robots that can be used as surgical tools, sensing
machines to explore disaster zones or manufacturing tools to assemble
micro-machines.
“It’s very gratifying to first be noticed by an
international company and second to work on something like this where you can
see immediately how it might be used,” says Rao, who earned her Ph.D in 2009 at
UT Arlington. “However, I think we’ve only scratched the surface on how these
micro-windmills might be used.”
The micro windmills were tested
successfully in September 2013 in Chiao’s lab. The windmills operate under
strong artificial winds without any fracture in the material because of the
durable nickel alloy and smart aerodynamic design.
“The problem most MEMS
designers have is that materials are too brittle,” Rao says. “With the nickel
alloy, we don’t have that same issue. They’re very, very durable.”
The
micro-windmills can be made in an array using the batch processes. The
fabrication cost of making one device is the same as making hundreds or
thousands on a single wafer, which enables for mass production of very
inexpensive systems.
“Imagine that they can be cheaply made on the
surfaces of portable electronics,” Chiao says, “so you can place them on a
sleeve for your smart phone. When the phone is out of battery power, all you
need to do is to put on the sleeve, wave the phone in the air for a few minutes
and you can use the phone again.”
Chiao says because of the small sizes,
flat panels with thousand of windmills could be made and mounted on the walls of
houses or building to harvest energy for lighting, security or environmental
sensing and wireless communication.
He adds that it has been fulfilling
to see his former student succeed and help move innovation toward the
marketplace.
“To see a company recognize that and seek you out for your
expertise speaks volumes about what UT Arlington means to the world,” he
says.
Release Date: January 10, 2014
Source: UT
Arlington


