Tech Briefs Magazine - October 2023 - 28

Electrical/Electronics
than a bare hand, for instance. The
switches will automatically adjust themselves
so that multiple devices installed
close together will not affect each other
through mutual interference.
Intelligent electronics enable the device
to drive an integrated two-color LED
ring, which can be red/green or blue/
white, the latter being more visible to
people regardless of their color vision.
Designers can configure the illumination
and color status of the ring to provide
users with visual feedback that a
switch operation has occurred, or to indicate
a standby state (Figure 2).
Because touchless switches
include
both detection and visualization capabilities,
a single device can effectively be
used to replace one sensor switch and
two LED lamp indicators, saving installation
space and overall cost. These touchless
switches also incorporate the following
features:
* solid-state optically isolated relay output
*
selectable for a 0.5 second on-delay
and 2.0 second off-delay timer, or direct
acting
* operates at 12 to 24 VDC, with 100mA
max load current and reverse connection
protection
* installed in industry-standard 22-mm
mounting holes, available in black plastic
resin or silver aluminum alloy
* rated IP65/67 and UL Type 4X, and
suitable for outdoor use.
Touchless switches can be affected by
direct sunlight, dirt, and water in a way
that could provide false signaling, so designers
need to review the specifications
for their applications. However, these
devices help designers create hygienic
systems, while avoiding costly provisions
required by traditional devices.
Touchless switches are an ideal solution
for industries such as food, beverage,
pharmaceuticals,
medical, and
chemicals where sanitary design is important.
They are also useful for protecting
the well-being of users in everyday
commercial applications, such as vending
machines, elevators, ATMs, and anyplace
where pushbuttons are needed.
This article was written by Luiz Shida,
Marketing Specialist, IDEC Corporation
(Sunnyvale, CA). For more information,
visit https://us.idec.com.
A Vertical Electrochemical Transistor to Revolutionize
Bioelectronics
Potential applications include measuring heartbeat and levels of sodium and potassium in
blood, as well as eye motion for studying sleep disorders.
Northwestern University, Evanston, IL
A
Northwestern
University
research
team has developed a revolutionary
transistor that is expected be ideal for
lightweight, flexible, high-performance
bioelectronics. The electrochemical
transistor is compatible with blood and
water and can amplify important signals.
Such a transistor could enable wearable
devices for onsite signal processing
- right at the biology-device interface.
Potential applications include measuring
heartbeat and levels of sodium and
potassium in blood, as well as eye motion
for studying sleep disorders.
" All modern electronics use transistors,
which rapidly turn current on and
off, " said co-corresponding author Tobin
J. Marks. " Here we use chemistry to
enhance the switching. Our electrochemical
transistor takes performance
to a totally new level. You have all the
properties of a conventional transistor
but far higher transconductance [a measure
of the amplification it can deliver],
ultra-stable cycling of the switching
properties, a small footprint that can enable
high density integration, and easy,
low-cost fabrication. "
The vertical electrochemical transistor
is based on a new kind of electronic
polymer and a vertical - as opposed to
planar - architecture, and it conducts
28
The vertical electrochemical transistor is based on a new kind of electronic polymer and a vertical,
instead of planar, architecture. (Image: Northwestern.edu)
both electricity and ions and is stable
in air. The work was published in the
journal Nature.
" This exciting new type of transistor
allows us to speak the language of both
biological systems, which often communicate
via ionic signaling, and electronic
systems, which communicate with elecwww.techbriefs.com
trons, "
said Professor Jonathan Rivnay.
" The ability of the transistors to work
very efficiently as 'mixed conductors'
makes them attractive for bioelectronic
diagnostics and therapies. "
" With their vertical architecture, our
electrochemical transistors can be
stacked one on top of another, " said
Tech Briefs, October 2023

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Tech Briefs Magazine - October 2023

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