Last year, researchers from the US and Canada reported in PLOS ONE creating electrical batteries from ice. The electrical output is modest, just 0.1 milliwatt. But this may be a sign of good things to come. The scientists worked over the course of two seasons to design and produce electrochemical cells that will work to generate electricity.

Dr. Daniel Helman and Dr. Matthew Retallack met at the European Consortium for Political Research in Montreal, Canada in 2015. Helman was presenting ideas about solar panels from ice, and Retallack was the discussant of the session.

“I think there was a mutual respect and love of research,” says Helman. They went on to develop different prototypes. The model that finally won out uses acid to create a difference in pH between two layers of ice plus a few additives.

The most mobile charge carrier in ice is the proton, so it makes sense to think of protons traveling from one layer to the other because of the pH difference. The travel of charged particles is how batteries generate electricity.

In this case, table salt, kaolinite clay and monopotassium phosphate help to donate or receive charged particles, along with muriatic acid (HCl). A mesh screen and sheet aluminum were used as the electrodes.

The materials used in the experiments are all commonly available, and commonly regarded as safe. It makes one wonder what would be possible using more optimized materials. Moreover, photosensitive particles added in can probably produce dye-sensitized solar cells.

The original experiments for dye-sensitized solar cells used chlorophyll taken from spinach to change local pH in response to sunlight. While the electrical output may be small, the point is not lost that large swaths of land at high latitudes might be available.

Fields, lakes or other open land might be safely put to good use in humanity’s quest to transition away from fossil fuels. The additives in this experiment were chosen for their relative safety in the environment.

The generation of electricity from ice also sheds light on one of the more enduring questions facing science right now. Where did life come from? Current thought is that organisms originated either in small ponds near volcanic, geothermal fields, or near mid-ocean ridges. But there is a problem. RNA gets diluted without a membrane, and then cannot act as a catalyst.

An icy setting solves this problem. RNA may remain concentrated in small regions on, for example, the ice of a comet or meteorite. Thus, generation of electricity from ice could provide a proto-metabolism for the start of organismal development with self-catalyzing RNA on such icy meteorites (like the Murchison meteorite) or on an early Snowball Earth.

Both of these ideas are not so far fetched. Solar panels from ice may be useful in some settings. And an icy worlds hypothesis for the origin of life may explain why we don’t see any of the early stages here on Earth now.

Dr. Helman is currently a visiting assistant professor of Environmental Studies at Wofford College in Spartanburg, South Carolina. Dr. Retallack ran the experiments while at Carleton University in Toronto.

Provided by
Wofford College

How can virtual reality (VR) be experienced haptically, i.e., through the sense of touch? This is one of the fundamental questions that modern VR research is investigating.

Computer scientist André Zenner, who is based in Saarbrücken, Germany, has come a significant step closer to answering this question in his doctoral thesis—by inventing new devices and developing software-based techniques inspired by human perception. He has now been awarded the “Best Dissertation Award” at the world’s leading VR conference.

The award-winning work is about how physical props (technical term: “proxies”) can be used to make objects in virtual environments tangible.

“Of course, you can’t have a proxy for every virtual object, then the approach wouldn’t be scalable. In my dissertation, I, therefore, thought about what devices could look like that could be used to simulate the physical properties of several different virtual objects as effectively as possible,” explains Zenner, who completed his doctorate at the Saarbrücken Graduate School of Computer Science at Saarland University and is now conducting research at Saarland University and the German Research Center for Artificial Intelligence.

This resulted in the prototypes for two special VR controllers, “Shifty” and “Drag:on.” VR controllers are devices that can be held in the user’s hand to control or manipulate objects in virtual reality using tracking technology.

“Shifty” is a tubular controller in which a movable weight is installed. The weight can be moved along the lengthwise axis by a motor, changing the center of gravity and inertia of the rod.

“In combination with corresponding visualizations in virtual reality, Shifty can be used to create the illusion that a virtual object is getting longer or heavier,” explains Zenner. In experiments, he was able to prove that objects are perceived as lighter or smaller when the weight is close to the user’s hand and that, coupled with the corresponding visual input; they are perceived as longer and heavier the further the weight in the rod moves away from the user.

“This is mainly due to changes in the inertia of the controller, as the overall weight does not change,” explains Zenner. The research and development department of gaming giant Sony is already experimenting with this concept and cites Zenner’s work in the development of new VR controllers.

The second controller, “Drag:on,” consists of two flamenco fans that can be unfolded using servomotors, thus increasing the air resistance of the controller. This means that the further the fans are unfolded, the more force the user has to exert to move the controller through the air.

“Coupled with the right visual stimuli, Drag:on can be used to create the impression that the user is holding a small shovel or a large paddle, for example, or that they are pushing a heavy trolley or are twisting a knob that is difficult to turn,” explains Zenner.

Both controllers are basic research and so-called “proof of concepts.” This means that the prototypes can be used to show in user experiments that different controller states can improve the perception of different VR objects. Still, specific products using this technology are not yet available on the market.

With the controllers, the Saarbrücken-based computer scientist first addressed the so-called ‘similarity problem.” The aim here is to ensure that virtual and real objects feel as similar as possible. In the second part of his work, he dealt with the so-called “colocation problem,” i.e., the question of how the proxy can be spatially located in real life where the user sees it in virtual reality.

This is particularly challenging as the controllers act as proxies for different virtual objects. Consequently, the user must be given the illusion that they are reaching for various objects, although in reality, they will always grasp the same proxy.

To achieve this, the researcher made use of the already established method of “hand redirection.” As the name suggests, this involves redirecting the movement of the hand in virtual reality so that the user thinks they are reaching to the left, for example, even though they are actually stretching their hand forward.

“We conducted experiments to investigate the point at which users realize that their hand has been redirected. Our results showed that this point was reached quickly, so we thought about how we could better conceal the hand redirection,” says Zenner.

The solution: he tricked the brain by only redirecting the hand when the brain was blind to visual changes—namely during blinking. Together with a student under his supervision, he developed the appropriate software and used the eye trackers built into many VR headsets.

In control studies, the team was then able to show that their new controllers, in combination with hand redirection algorithms, led to more convincing VR perceptions than previously possible.

Provided by
Universität des Saarlandes