The Light Side

The Light Side: A Cloaking Device Hiding in Plain Sight

October 2, 2014

Plus: Scrobby -- A Robot to Scrub Solar Panels; and Apple's PR Stress and Product Strain from 'Bendgate'

Lens1Cloaking, once a technology reserved only for witches, wizards, and modern material scientists, may be coming to a home near you thanks to a recent development by optical engineers.

In the past decade researchers have made steady progress developing technologies that produce varying levels of cloaking. While these efforts have been groundbreaking and successful, they've relied on exotic materials that are expensive to produce. As cloaking tech continued toward ever increasing complexity, however, researchers at the University of Rochester created a simple, easy way to build a cloaking device.

Constructed from a series of four lenses, the cloak is made possible through the precise positioning of each optical component. When coupled in a specific series, two f1 and two f2 lenses can be aligned to make an object passing through their view disappear. What's astounding about the Univ. of Rochester design is not just its simplicity but also its ability to obscure objects regardless of a user's viewing angle. In previous cloaking technologies, exacting viewing angles were required to achieve the desired effect, rendering them a bit useless.

That is not the case with this new optical design. In addition to its wide field of view, the Univ. of Rochester cloak has the ability to scale up as the diameter of its lenses increase.

While the cloak is, without question, a major leap forward in cloaking tech, it's far from perfect. "This cloak bends light and sends it through the center of the device, so the on-axis region cannot be blocked or cloaked," said Joseph Choi. What Choi means is that in his team's initial iteration of their design, a doughnut-shaped field was rendered invisible, while a small central section escaped the cloak's cover. However, with a bit of tweaking and a slightly more complicated design, that artifact has been removed.

Though cloaking of the university's variety might seem to have few practical applications, the team was quick to point out that their discovery could make a major difference in everyday life. Armed with cloaking spectacles, surgeons could see through their hands to better observe what they're working on. Furthermore, semi-truck drivers could employ the same tools to eliminate blind spots, making highways much safer for everyone.

If you're interested in building your own invisibility cloak, Univ. of Rochester's engineers were kind enough to provide instructions.

1.       Purchase two sets of two lenses with different focal lengths f1 and f2 (four lenses total, two with f1 focal length, and two with f2 focal length).

2.       Separate the first two lenses by the sum of their focal lengths. (So f1 lens is the first lens, f2 is the second lens, and they are separated by t1= f1+ f2.)

3.       Do the same for the other two lenses.

4.       Separate the two sets by t2=2 f2 (f1+ f2) / (f1- f2) apart, so that the two f2 lenses are t2 apart.

This article was originally published on Engineering.com and is adapted in its entirety with permission. For more stories like this please visit Engineering.com.

Scrobby -- A Robot to Scrub Solar Panels

Stefan Hamminga spent just enough time cleaning his solar modules to learn that he didn't want to clean his solar modules anymore. He decided the job was fit for a robot and his solution is Scrobby Solar, a robot designed to clean solar panels.

Scrobby works when its sensors detect rain, scrubbing the panel surface and moving back and forth across the field. When the rain stops Scrobby goes back to its resting platform. Gravity and motors propel the robot back and forth the panels by manipulating the unit's suspension wires.

My first reaction to seeing this was the unit itself would be blocking valuable surface area and hamper the array's energy production. The resting panel on the side houses Scrobby without taking away any efficiency.

The body of the Scrobby is 240 millimeters in diameter, and 67 total millimeters high. Full weight of the unit is 1.2 kilograms. Up to a 10 meter by 20 meter surface area can be serviced by the unit. Inclination angles between 20 and 75 degrees will work with the device.

One great part of the Kickstarter campaign video is the prototype process. Hamminga is shown going through the development and a few iterations of building a working prototype. Additionally seeing the Scrobby in action is great, watching the motors and sensors move the unit across the surface of a solar array.

Hamminga's Kickstarter funding campaign is running until October 11, 2014 and as of this writing still needs more than €60,000 to be successfully funded. So far this is a disappointing turnout for a device that can revolutionize solar panel maintenance the way that the Roomba changed the way several of us vacuum.

This article was originally published on Engineering.com and is adapted in its entirety with permission. For more stories like this please visit Engineering.com.

Apple's PR Stress and Product Strain from 'Bendgate' 

Can an unstoppable force bend an immovable object? We don't know, but a bendable iPhone could be enough to short-circuit Apple's sales of its once-peerless, once-unstoppable iconic device. The rollout of the iPhone 6 and iPhone 6 Plus started off very well, busting the 10 million unit sales mark over its opening weekend, with fanboys and fangirls having camped out in front of Apple Stores and salivated over the bigger screen and premium-feel aluminum body.

Ah, that aluminum body. As CNN noted, aluminum "is a naturally flexible material," a point it made in a report covering the trials and tribulations of "Bendgate." If you have been sleeping under a rock, all hell broke loose after an Internet tech guru posted a video of him being able to bend his newly acquired iPhone 6. Since then, intrepid reporters, consumers, and generally everyone looking for their 15 minutes of fame have gone to Apple Stores in attempts to bend display models and document their experiences on video. Bendgate videos have been less forthcoming, since who'd want to kill a $750 phone he or she just bought?

Apple hasn't exactly gone to DEFCON 5 over the Bendgate controversy -- probably a 2 or somewhere just under 3. The company admitted that there have been nine confirmed cases of bending iPhones but assured that the new phones have aluminum bodies that have been tempered for extra strength. Batch problem or not, by Apple's official count, we say nine out of 10-million-plus units is a pretty damn good bend rate that does not qualify for the "gate" suffix. But tell that to the nine-without-a-doubt disappointed Apple disciples, and there are plenty of "unconfirmed" bends on the Internets.

Since the reports began circulating, public service announcements for iPhone 6 new owners have included not to sit on them and keep them too long in the pockets of skinny jeans, which is a very helpful message for both women and men in New York City. "With normal use a bend in iPhone is extremely rare," Apple stated; we don't know if that excludes storage in tight-fitting clothing. But rival Samsung found Bendgate amusing enough to roll out an ad showing its Galaxy Note 4 survive a 55-pound gluteus maximus test.

With the streams of thrill-seekers still heading to Apple Stores in search of a bendable iPhone, maybe Apple should start posting "Bend But Don't Break" policy signs, followed by "You Break It, You Buy It" disclaimers.

 

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