Peratech is now customising its QTC force sensors to meet the requirements of the next generation of notebook PCs. QTC sensors, which consist of nanoparticles printed and encapsulated in ultrathin (down to 50 µm) polymer membranes, can be configured to sense an X-Y position when touched lightly and measure the force in the Z-axis as more pressure is applied. The response to pressure is predictable, repeatable and consistent over time. As a result, QTC force sensors offer the design flexibility required to create optimal interfaces in response to evolving user demands.

In trackpads, single point force sensors are a cost effective means for enabling a variable force input, with X-Y positioning still provided by capacitive sensing and tactile response from a microswitch or dome. Alternatively, integrating a 3D multi-touch force-sensing matrix into the trackpad delivers position and pressure data for every individual touch point.

QTC force sensors can be used under the space bar to create a linear scrolling function while providing X-position data. Cursor keys can be made more versatile, with changes in pressure being used to vary both scrolling speed and cursor speed. A similar approach is possible with function keys. By installing force sensors beneath them, volume and brightness can be pressure-controlled. The adjustment speed is improved by pressing gently to increase or decrease slowly, and pressing harder to adjust more quickly.

The power button can be made smarter too. For example, a light touch could put a notebook to sleep while a hard press powers it off. Similarly, a QTC sensor can be placed below a fingerprint sensor so that the computer can wake from a press of the button before the scan takes place. This means that the user only has to press one button, rather than two, to wake up a notebook.

Peratech’s Chief Commercial Officer, Mike Levin, said, “Every time we meet with designers and engineers, creative new ways for user interaction come into the conversation. Force sensing can be implemented at low cost, with minimal mechanical issues because the sensors are extremely thin and work underneath most surfaces. QTC sensors can not only be integrated as a primary touch interface, but can also improve the user experience when combined with complementary technologies such as capacitive sensing.”