Method and device for producing a key-click effect on a haptic interface

A method for producing haptic feedback via a squeeze-film effect on a haptic interface equipped with electromechanical actuators that are configured to apply, to said haptic interface, ultrasonic vibrations able to create standing waves at resonant frequencies of the haptic interface, comprising the steps of:

• a. in a preliminary phase of characterization of the haptic interface, determining a subset of resonant frequencies fi of the haptic interface in the ultrasonic domain;
• b. defining a haptic sequence consisting of an electrical excitation signal s(t) formed by at least two successive periodic signals constituting wave trains of respective frequencies fi, fj that are different from each other and that belong to said subset of resonant frequencies of the haptic interface, wherein two successive wave trains of the signal s(t) are separated by a dead time without excitation, of a duration between 0.1 ms and 15 ms;
• c. in a phase of use, detecting a static touching action of a user on a region of a surface of the haptic interface;
• and
• d. in response to said detection, exciting the electromechanical actuators using said electrical excitation signal s(t), so as to achieve a transition from a first standing wave to a second standing wave on the haptic surface, to produce, on the haptic surface, lateral forces that cause the user to feel a key-click sensation.