A researcher with the University of Buffalo's Virtual Reality Lab uses the fingertip digitizer as a probe to estimate the shape and material properties of a soft object.

A researcher with the University of Buffalo's Virtual Reality Lab uses the fingertip digitizer as a probe to estimate the shape and material properties of a soft object.


According to Associate Professor of Mechanical and Aerospace Engineering, Thenkurussi Kesavada, "Screens and pads limit users to dragging or pressing, so the systems cannot capture common tactile activities like rubbing and scratching. In contrast, the digitizer lets users poke and prod objects to model complex biomechanical characteristics at the fingertip, such as joint impedance and viscoelastic tissue behavior, or how tissues conform to surfaces they touch. Any touch or patterned fingermotion makes valid input."

One application has the device acting as a 3D-object digitizer. In this case, it replaces a traditional probe stylus and captures the hardness and texture of objects as well as their 3D shapes. Another application is humancomputer interaction. For example, users can touch a fluid's surface and the digitizer system solves Navier-Stokes equations to simulate the motion of particles in the fluid. Users can then intuitively "see" surface waves and movements on the computer screen.

The digitizer can also function as a mouse, joystick, or keyboard. To act as a mouse, the digitizer captures the force, acceleration, and velocity of the fingertip to deduce which file or folder the user is pointing to on the desktop, and where to move the file. For more artistic applications, users can draw or paint directly on a touch-canvas screen. Here, contact position, force, and acceleration are the important inputs. For instance, users can simulate splashing of paint by a simple jerk of the finger.