Last June at Darnell’s Nanopower Forum, Face International
demonstrated prototypes of its Lightning remote switching
technology for home and business wiring (see “Zombies And
Energy Harvesting” at www.electronicdesign.com, ED Online
15788). At that conference, Lightning was essentially a charge stored
in clouds of hope. By the time of this year’s conference, though,
Lightning had struck.
During the interim, the company turned the technology’s potential
into actual sales of a range of products suitable for everything from
retrofitting home light switching to allowing casino dealers to surreptitiously
summon security agents. Face International, which still holds
the NASA patent, spun the product business off as Lightning Switch, which is a more memorable
name.
The Lightning Switch
technology evolved from
a NASA technology called
Thunder, which was developed
to create piezoelectric
linear actuators with a relatively
long throw. Being piezoelectric,
the process is reversible. Lightning
turns Thunder on its head,
enabling the company to create
switches with a long, satisfying
mechanical “feel.” These switches
can harvest enough electrical
energy from each activation to
power their own mesh network
nodes, allowing remote control
of whatever utility-powered
device the end-user wishes.
The inverted-Thunder core
technology addresses the problem
of displacement in piezoelectric
materials—how do you
harvest a significant amount of
piezoelectric energy while providing
tactile feedback in a pushbutton
switch? Essentially, Lightning
answers the question with a thin ceramic piezoelectric wafer, sandwiched
between an aluminum sheet and a steel sheet.
The “mayonnaise” in this piezoelectric sandwich is a thermoplastic
adhesive. The process heats the adhesive to set it and permits the
now-bonded structure to cool, bending and pre-stressing the piezo
material. This provides a good quarter-inch of travel as well as enough
energy to flash three NE-2 neon lamps in a tabletop demonstration
(see the figure).
The value proposition for the technology lies in reducing construction
costs. In one case, a 71,000-square-foot industrial facility needed
21 banks of lighting with associated control. The contractor originally
bid $63,000, based mostly on the labor and overhead costs of installing
more than a mile of couduit and switch wire. The contractor then
bid again and won, using various Lightning products to complete the
job for $10,000 for materials and 10 hours of labor.
LIGHTNING SWITCH
www.lightningswitch.com