From Smartphone to 3D Printer
At present, if you want to create something using a 3D printer, you first generate a digital model using a
software package like Blender, OpenSCAD, or even
AutoCAD. However, the process eventually may be as
simple as taking a photo of something using your
smartphone and sending the data to the printer, thanks
to a camera chip developed at the California Institute of
Technology ( www.caltech.edu).
Your existing camera basically just catches pixels of
incoming light without reference to how far away an
object is. The Cal Tech chip — called a nanophotonic
coherent imager (NCI) — uses LIDAR, which illuminates
the target with a laser and analyzes the reflected light to
provide both distance and intensity data.
"By having an array of tiny LIDARs on our coherent
imager, we can simultaneously image different parts of
an object or a scene without the need for any
mechanical movements within the imager," noted
developer Prof. Ali Hajimiri.
Using coherent light, it is possible to detect the
phase, frequency, and intensity of the reflected light
from different points on the object, which is sufficient
information to create a highly accurate 3D image. In the
illustration, micrometer-scale resolution was obtained on
a penny from a distance of about 1.5 ft (0.5 m).
The prototype NCI consists of an array of only 16
coherent pixels, which isn't all that useful. In fact, the
image of the penny was created from a series of 4 x 4
pixel sections. Hajimiri says the current array of 16 pixels
could be easily scaled up to hundreds of thousands.
With these larger arrays, the imager "could be
applied to a broad range of applications from very
precise 3D scanning and printing, to helping driverless
cars avoid collisions, to improving motion sensitivity in
superfine human machine interfaces."▲
Method for Cancelling Shockwaves
In today's conditions of asymmetric warfare, explosive devices pose a major hazard to soldiers and equipment.
Most of the damage is created by two threats: flying shrapnel
and shockwaves. Shrapnel often can be handled using armor
and other physical barriers, but shockwaves are more difficult
to deal with. By definition, shockwaves are "traveling
discontinuities in pressure, temperature, density, and other
physical qualities through a medium," and they can pass
through intermediate media.
However, it was recently reported that Boeing Co.
( www.boeing.com) has been working on a method of
creating a shock-attenuating force field and, in fact, recently
was issued a patent on its "Method and system for
shockwave attenuation via electromagnetic arc."
One is tempted to think in terms of a force field such as
popularized in science fiction, but in reality it is more
analogous to the operating principles of a noise-cancelling
microphone. In the Boeing concept, the system — perhaps
mounted on a Humvee — visually detects and analyzes an
explosion, then before the resulting shockwave can reach the
vehicle, creates an opposing protective shockwave.
It does so by sending out laser pulses that ionize the
intervening air and forms a plasma channel. The channel —
via deflection, absorption, reflection, and refraction —
minimizes damage to the vehicle.
There is no indication of when or if such a system will
be ready for deployment, but there is no reason why it can't
also be applied to aircraft, naval ships, and even buildings. ▲
■ Illustration of shockwave attenuation system from
■ BY JEFF ECKERT TECHKNOWLEDGEY 2015
8 August 2015
resolution of a penny
taken from 1.5 ft away.