NEWS & TECHNOLOGY SENSORS
Bio-inspired arrayed camera is only 740μm thick
FBy Julien Happich ollowing up on previously reported
bio-inspired multi-faceted microcamera
designs, researchers from the
Korea Advanced Institute of Science and
Technology (KAIST) have shrunk their camera
stack to a total track length of 740μm.
In a paper titled “Biologically inspired ultrathin
arrayed camera for high-contrast and
high-resolution imaging” published in Nature’s
Light Science & Applications journal,
Structure of the Xenos peckii’s eye (left)
comprising facet lenses (FL), pigmented
cups (PC), and photoreceptors (Prs),
versus the bio-inspired ultrathin camera
(right).
the researchers achieve high-contrast and
super-resolution imaging thanks to a novel arrayed design of
micro-optical elements (MOEs) comprising multilayered aperture
arrays (MAAs) and inverted microlens arrays (iMLAs) directly
stacked over an image sensor. The MOEs were fabricated using
simple sequential photolithography and thermal reflow steps on
a glass substrate, which was then flipped over and integrated
on a CMOS image sensor with gap spacers.
This camera stack was directly inspired from the eye structures
of paper wasp specie Xenos peckii, featuring hundreds of
photoreceptors behind each individual eyelet. Such a structural
arrangement is reported to offer higher visual acuity than other
compound eyes found in nature.
As the authors report in the paper, with a total track length
of 740μm including the top glass window, the fully packaged
camera boasted a field-of-view (FOV) of 73° and enabled highcontrast
imaging by eliminating the optical crosstalk between
neighbouring microlenses.
The MAAs, stacking UV patterned black polymer circular
patterns, serve as cylindrical pinhole arrays, which provide efficient
light absorption over the whole visible spectrum and thus
substantially reduce the optical crosstalk between microlenses,
the paper reads.
What’s more, with their novel optical stack configuration,
the researchers are able to precisely control image overlap
between neighbouring channels, simply adjusting the period of
the microlenses. This overlap makes the images arrayed from
multiple channels uniform but all slightly different, from which a
single high-resolution
image can be
reconstructed using
a dedicated multiframe
Detail of the bio-inspired ultrathin
camera optoelectronic stack, showing
inverted microlens arrays (iMLAs) in
place of facet lenses, multilayered
aperture arrays (MAAs) in place of
pigmented cups, gap spacers, and
CMOS image sensor arrays (CMOS ISA)
in place of the photoreceptors.
super-resolution
algorithm.
This ultrathin arrayed
camera could readily find practical use in mobile devices,
advanced surveillance vehicles and endoscopes, the authors
conclude.
The fully packaged ultra-thin arrayed camera.
Multi-touch sensor vendor funded for consumer pivot
PBy Peter Clarke ressure-sensitive touch grid vendor Sensel Inc. (Sunnyvale,
Calif.) has raised $28 million in a Series A round of
equity financing.
Sensel was founded in 2013 by Ilya
Rosenberg and Aaron Zarraga and focused
its initial work on the developing
the Morph multi-point touch surface and
applying it to audio studio equipment.
The technology provides the ability to
detect touch force as light as 1gm up
to as heavy as 5kg. It comes in foldable
thin film form allowing it to provide soft
buttons on the edge of rounded surfaces.
It works with finger, paint brush, passive stylus, finger nails
or a gloved hand. Firmware can provide such features as palm
rejection improving pen or stylus operation. The latest round of
funding brings the total invested in Sensel to $38 million. Investors
include: Susquehanna International Group, Morningside
Group, SMiT, Palm Commerce Holdings
Co. Ltd, Chariot Gold Limited, SV Tech
Ventures and Innolinks Ventures.
The company has been showing a
prototype of its PressureGrid technology
applied to a mobile phone and the funding
is likely intended to help this transition
to a much bigger consumer market
including phones and tablet computers.
“Since Sense’s founding in 2013,
we’ve worked tirelessly to create a
sensor that outperforms existing touch technologies on every
metric and at a lower overall cost,” CEO Rosenberg said in a
statement.
20 News March 2020 @eeNewsEurope www.eenewseurope.com
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