Miscellaneous, Science & Technology

T Cubed: Solar Cells and Tablet PC Virtualization

Note: This article is hosted here for archival purposes only. It does not necessarily represent the values of the Iron Warrior or Waterloo Engineering Society in the present day.

Higher resolution, more power, better software and more features are all selling points we hear about when smartphone and tablet manufacturers are selling us their new shiny devices. We hear a lot about how phones can last a whole day or sometimes up to a couple days, but we don’t hear a lot about these devices lasting longer. A week is almost unheard of when it comes to the life of smartphones and tablets, but wouldn’t it be incredible if you didn’t have to charge them at all?

Arokia Nathan and his team at the University of Cambridge have been working with the goal of resolving the need to charge devices more often. Arman Ahnood, who is a researcher on the team, told scientists at the Materials Research Society meeting last fall that they may have begun to find a way to prolong the battery life of smartphones using solar cells.

The team created a prototype that turns ambient light into electricity, using solar cells made of thin, hydrogenated amorphous silicon that sits in the screen of the phone. In most OLED displays, the end user only sees about 36 percent of the light generated, with the rest of it escaping from the edges of the OLED. By placing thin, photovoltaic cells on around the edges of the display, this energy can be captured and used to power the device.

Using this energy to charge the device could be an issue, since the solar cell would be feeding varying levels of energy to the battery, which could ultimately damage the battery. The researchers found a way to get around this by using a thin-film transistor circuit to dampen voltage spikes. The solar cells also don’t directly charge the battery, but instead feed to a thin-film supercapacitor for intermediate storage.

Currently, the system has an efficiency of 11 percent on average, so for a smartphone with a 3.7-inch screen, it generates about 5 milliwatts. While that’s only a fraction of the power smartphones use, the team’s next goal is to find other designs and materials that can push efficiency up to 90%, which could allow the phone to last a few hours longer. In time, they hope to be able to create phones that don’t need to be charged. In my view, this could be used in tablets as well, which usually have 7-inch or 10-inch displays.

Tablets are an excellent segue into my vaguely-related but still technical second topic for this issue, which was announced a couple weeks ago. OnLive, a cloud service company currently offering streaming video games to the masses, wants to try expanding to virtualized Windows desktops on tablets with OnLive Desktop. While the service has been released in the United States, it is not yet in Canada, and I also don’t have an iPad, so I’ve gathered impressions from Americans who have been able to use the service so far.

OnLive Desktop comes in two tiers: free and $10/month. The free version, which is the only one available at the time of this article’s release, allows you to remotely operate Windows 7 with 2 GB of storage and access to Word, PowerPoint and Excel. The paid version gives users 50 GB of storage and allows installation of extra applications.

Since the version of Windows 7 used is Windows 7 Touch, which is specifically designed for touchscreen devices, it comes included with Microsoft Surface applications and games in addition to the aforementioned Microsoft Office package. One of the primary applications not included, which was a major gripe for some users, was a web browser. While there’s always the option to go back to the iPad home menu and launch Safari, then go back to OnLive Desktop when you’re done, it takes you out of the virtual desktop experience and will be unsatisfactory for some users of the service. Even without the web browser, users can still transfer files to the virtual desktop through OnLive’s website, which places the files onto the virtual machine.

Another major issue users had was the streaming quality. One reviewer claimed that it was not necessarily the Internet connection that determined the video quality but how much data you were sending at one time. One-way tasks, such as watching videos and viewing documents, had high quality levels since data is not being sent both ways. When a user is typing however, or heavily interacting, the quality streamed back to the iPad was substandard. The Windows on-screen keyboard (not the one that iPad users usually use, but the one you use in OnLive) was generally disliked and many reviewers suggested using a Bluetooth keyboard instead to interact with the application.

Even with these issues, many people found that the service showed promise and was able to do some things quite well. While the streaming quality wasn’t ideal, this is still the only major application doing anything like this, and the service’s potential could be even greater. With support coming to Android tablets, Windows, OS X and even smartphones in the future, it’s not unrealistic to see a service like this being the only way many people interact with traditional desktop operating systems in the future. If you have a decent Internet connection, why buy a laptop if your tablet can run the few desktop-class applications you need?

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