APR-type transducers

Acoustic pulse recognition (APR) technology was developed by SoundTouch Ltd in the early 2000s and introduced to the market by ELO in 2006. Unictron’s piezoelectric transducers are developed to be used in APR type touch panel of various sizes. Custom-made specifications or designs are available. Unictron’s piezoceramic elements are recognized for the high quality, durability and lower cost.
Piezo elements for APR touch panels
The piezoelectric transducer is used in APR type touch panels to determine a “touch point” by converting mechanical energy into electrical signals. The APR type touch panel consists of a glass plate with several piezoelectric transducers attached to the edges of the touch screen. When touching the surface of the glass by a finger or stylus, bending waves are induced that radiate away from the touch location. The transducers pick up the acoustic waves and transform them into electrical signals. The signals are digitized by the controller and compared to a prerecorded acoustic profile for every position on the panel. Thus the touch location is determined. APR type touch panel is usually able to function with scratches and dust on the screen and also shows good position resolution and accuracy. This technology is also very suitable for displays which are physically larger.

Unictron’s APR type thick film transducer elements can be designed to fit touch panels of various sizes. Custom-made specifications or custom-made designs are also available.



  • Piezoceramic sensors for the acoustic signal pick-up in APR type touch panels.


  • Better light transmission
  • Excellent durability and reliability
  • High resolution and positional accuracy
  • Lower cost



Resonant Frequency

(nF) at 1 kHz

Operating temperature range

tan δ

16 x 3 x 0.4

5.50 ± 0.30

1.55 ± 20%

-10 ~ +60


* Other dimensions are available upon request.

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