As the metal does not change its length the stripe bends upwards and lifts a little pin. The force applied by the piezocrystal can reliably withstand the mass of the finger. When the voltage is stopped, the strip returns to its normal shape and the pin is no longer raised. Because of the differences in orientation of the attenuators, piezocrystals cannot be built in arbitrarily large arrays. The advantages of a piezocrystal are low power consumption and low noise emission, which make it the preferred technology.
Several approaches exist for virtual Braille displays.
A virtual Braille display uses only one Braille module in combination with a pointing device. Another approach for a virtual Braille display is to put one Braille module into a little carriage that can be moved horizontally. Whenever a new position is reached it is detected by the computer and a new character is displayed. While cost effective, none of the currently tested virtual Braille displays has been suitable for the majority of Braille readers. A transitory Braille display with 80 modules can display exactly one line of text shown on an Apple II computer, IBM PC or compatible.