TDK has introduced a piezo actuator that it claims offers an enhanced sensory experience through a responsive haptic feedback and an integrated sensor.

The actuator is based on multilayer piezo plates with copper inner electrodes. With multilayer technology, the actuator can be driven with relatively low operating voltages up to 120V. When activated, the piezo plates expand minimally in the z axis but, due to the constant volume of the piezo effect, contract simultaneously in both the x and y axes.

 
TDKPiezoactuators cr Figure 1: TDK claims unrivalled performance in terms of acceleration, force and response time and thus the quality of haptic feedback.  

The actuator employs cymbals on both sides of the plate as levers to amplify the contraction by a factor of 15 in the z axis. The actuator is available in two types, a 5N type that achieves up to 100µm displacement and a 20N type that can achieve more than 200µm displacement. Despite compact sizes of 12.7mm x 12.7mm x 1.6mm and 26mm x 26mm x 2.4mm, respectively, the actuators can generate forces of up to 5N and 20N.

Compared with typical electromagnetic solutions such as eccentric rotary motors (ERMs) and linear resonant actuators (LRAs), the piezo actuator features high acceleration and force, low insertion height and short response time. Under a load of 0.1kg, the 5N type delivers an acceleration of 5g with a rise time of 2ms while the 20N type features 15g after just 1ms.

The TDK piezo actuator has a stimulation range between 1Hz and 1kHz. It thus has frequency or amplitude limitations important in customising haptic feedback for users.

The product is targeted for use in vehicles, smartphones and tablets, household appliances, ATMs and vending machines, game controllers, industrial equipment and medical devices.