Using touch to trigger functions is an everyday occurrence; however, Setolic’s strain gauge technology makes it possible to apply touch functionality to almost any material, including rigid metals such as stainless steel and aluminium, glass, plastic, ceramics and wood. This allows a product to have keys printed directly onto its housing: when the user touches the keys, a slight deformation occurs in the material.

The strain gauge sensor network recognises even sensitive mechanical deformations to determine the location, pressure and duration of the press, then activate the key. The details of the pressure and duration of the press are also transferred, enabling multiple functions to be programmed from the same key.

The sensors for each key are mounted on a PCB, which in turn is mounted behind the housing material, resulting in a keypad that is completely sealed and has no moving parts. Offering IP69K ratings, the keypad is waterproof, durable and seamless. Additional functions such as LED illumination and haptic feedback can be included.

As the keys are operating a force sensor, measurements can be taken on the force applied to a given key. This means that a light touch can be differentiated from a firm, hard key press. The different press type can then be used to operate different functions, such as a volume control.

The keypads can incorporate visual feedback using LEDs and audio feedback. Additionally, the keypads can provide tactile feedback using an integrated vibration motor, which gives a different feel depending on the front surface material.

Typical applications include medical, transport and industrial equipment; household goods; products requiring special aesthetic design; and products that must be robust.


Strain gauge sensors