Researchers at Carnegie Mellon University and Microsoft have developed an acoustic biosensor that turns an arm into a crude touch screen.

An armband, worn around the bicep, detects minute sound waves that travel through skin when it is tapped. The researchers designed a software program that can distinguish the origin of the acoustic sounds--which vary due to slight differences in underlying bone density, mass and tissue. The system then translates these locations into button commands. A pico projector embedded in the armband projects a display--a game of Tetris or button controllers--onto a user's palm or arm.

The researchers found that they were able to achieve 95.5% accuracy with the controllers when five points on the arm were designated as buttons. They will present their results at this year's CHI conference next month.

See the researchers present Skinput below.

The Tangible, Embedded and Embodied Interaction (TEI '10) conference was held in Cambridge, MA, this week. Technologists and designers from around the world gathered to demonstrate projects exploring the blurring of physical and digital user interfaces. Here are some of the most interesting projects from the conference.

A Physically Responsive Map

This tabletop display shows 3-D shapes on a moving, flexible surface. The display changes shape in response to users' touch; for example, a map was projected onto miniature mountain ranges, and an image of the brain was contorted to reflect its shape.

"You could have an image of the body and dig into it and feel the heart beating," says MIT research assistant Daniel Leithinger, one of the creators of the project.

Interactive Art Cobots

Christian Cerrito, a graduate student at New York University's Interactive Telecommunications Program, is developing interactive art displays with collaborative robots called cobots. One of his cobots draws yellow circles until it receives an audio sound (someone clapping or shouting, for example), and then it draws a dashed line. Another changes its designs in response to light and shadow. In the future, Cerrito says he would like to use bigger robots in a public space for an interactive art exhibit.

A Tangible, Digital Jukebox

Researchers at the Music Technology Group of the Universitat Pompeu Fabra in Spain are using this project to explore the importance of physical objects associated to music--vinyl or CDs, for example. Their tabletop display consists of an infrared camera and projector beneath a sheet of Plexiglas. Small pieces of paper with dots underneath are traced by the camera below the glass. A user can use a piece of paper as a playlist.

An Augmented Reality Pattern Table

With this multiuser, augmented reality table, users can experiment with digital and physical patterns and shapes. A projector and infrared camera beneath the table lets a user "pick up" an image or video clip with plastic tiles and remix them to make new patterns. Arranging these augmented geometric tiles could give children a fun and interactive tool to learn about mathematical shapes, according to MIT graduate student Sean Follmer.

A Soap Bubble Display

This soap bubble display was designed by Axel Sylvester from the University of Hamburg and colleagues from the University of Duisburg-Essen in Germany.

The machine spits bubbles onto a soapy surface; below, a camera tracks the bubbles, which a user can move by blowing or gently dragging a finger. Moving the bubbles lets the user control lights, or images projected onto them. "We use it to think about the materiality of tangible [objects]," says Sylvester.

Videos by Kristina Grifantini, edited by Brittany Sauser

Yesterday, Google announced two changes to its search results page that it hopes will help people find what they're looking for without being overwhelmed by too much information. The changes are subtle and consist of extended snippets below the results as well as a handful of links at the bottom of the results page that suggest related searches.

The first change, which extends the description of the result below the blue-colored link, applies only if a person has typed in a long query. Usually when a person searches for keywords using Google, a two-line snippet, with bold keywords, shows up under the result link. The idea is that the snippet puts keywords in context, indicating whether or not the link is a good choice for the user. And the more of a snippet that's provided, the better choice a person can make.

The second change--the added links at the bottom of the page--reveals some of the common search terms associated with the keywords used. For instance, a search for "vitamin D" results in eight related searches, including "vitamin D deficiency" and "calcium."

This isn't the first time Google has changed its interface. Over the years, features such as easy, single-click search for images or news items containing keywords, and the ability to lift the ranking of a particular item in the search results, have crept in to the results page. But since its inception in 1998, Google's search interface has remained relatively static, sticking with a simple formula that has proven successful.

But bigger changes could be afoot. Last year, the company offered an "alternate views" experiment on the Google Labs page that essentially adds three search filters to a participants results page: "Info view," "Timeline view," and "Map View." While it's unclear that any of these features will stick, it indicates that Google engineers are testing dramatically different ways to serve up search results.