August 1, 2008 A non-mechanical haptic interface allows computer users to manipulate a three dimensional object on screen and receive immediate tactile response from the surroundings of that object. The interface uses a device shaped like an inverted umbrella, called a flotor, containing coils of wire. The user moves a control handle attached to the flotor, which interacts with the powerful magnets underneath. Circuitry routes the motion to the screen and responds when the object collides with something in the virtual world.
When you use a computer you're obviously able to see and hear the information on the screen. Now, you can touch it. A newly designed device lets computer users feel the texture and movement of what they are seeing in front of them.
Someday soon, a surgeon may perform computer-aided operations away from the operating room. A new device may give him the feedback he needs at his fingertips.
"What we use is a new form of magnetic levitation," says Ralph Hollis, haptics specialist at Carnegie Mellon University in Pittsburgh, Pa.
Dr. Hollis' specialization, haptics, is the science and technology of touch.
Dr. Hollis has developed a way to interact with 3D objects on a computer. A user grasps a handle inside a sphere attached to a desktop computer. The handle is connected to something that looks like an upside-down umbrella, called a flotor.
"That umbrella carries electrical coils, electrical current. These are immersed in high magnetic fields, created by a series of permanent magnets," Dr. Hollis explains.
The magnets allow the handle to float freely inside the sphere. It moves and rotates to control the position of the 3D object on the screen. When that object touches something in the virtual world, a user can feel it immediately.
Other haptic devices exist, but users must grab motorized arms to interact with the computer. With magnetic levitation, there's an almost direct connection between the user's hand and the software, giving immediate feedback. Just one more thing bringing the computer world into our world.
WHAT IS HAPTICS? Haptics is the term for incorporating touch in digital environments. It may be used to program resistance into a joystick for gaming, or to add a touch sensation to gloves used in a virtual reality environment. This way, when manipulating a virtual object, a user is able to be certain when it collides with another object, and not forced to rely on what they see. Compare what it is like to walk normally and when your foot has fallen asleep. Similar to the benefit of having full feeling in your feet, adding touch to a virtual environment makes interactions less awkward and more life-like.
WHAT MAKES MATERIALS MAGNETIC? Magnetism comes from the constant movement of charged electrons in atoms. As electrons swirl around an atom, they create an electrical current, and whenever electricity moves in a current, a magnetic field is created. So magnetism is a force between electric currents: two currents flowing in the same direction attract, while those pulling in opposite directions repel. The reason some materials are magnetic, while others are not, has to do with how the electrons are ordered. A magnet is an object made of magnetic materials; naturally occurring magnets are known as lodestones. Every magnet has at least one north pole and one south pole. In fact, if you take a bar magnet and break it into two pieces, each of the smaller pieces will still have a north and south pole. The Earth itself is a giant magnet with a north and south pole, which is why a magnetic compass's needle always points north/south.
The Human Factors and Ergonomics Society contributed to the information contained in the TV portion of this report.