The researchers say their PhonePoint Pen application uses the built-in accelerometers in cell phones to recognize human writing.
Accelerometers are the devices in phones that not only keep track of the phone's movements, but make it possible for the display screens to rotate from landscape to portrait modes depending on how the phone is rotated.
These devices are always "on," so there is no additional burden on the phone to use this new application.
"We developed an application that uses the built-in accelerometers in cell phones to recognize human writing," said Sandip Agrawal, electrical and computer engineering senior at Duke's Pratt School of Engineering, who with Duke graduate student Ionut Constandache developed the PhonePoint Pen.
"By holding the phone like a pen, you can write short messages or draw simple diagrams in the air.
Constandache said: "The accelerometer converts the gestures to images, which can be sent to any e-mail address for future reference."
"Also, say you're in a class and there is an interesting slide on the screen. We foresee being able to take a photo of the slide and write a quick note on it for future reference. The potential uses are practically limitless. That this prototype works validates the feasibility of such a pen," Constandache added.