Touch functionality has become an integral part of consumer electronics and various other products and touch switches (touch sensors) cannot be overstated. Traditionally, these switches have been capacitive, relying on the capacitance method (using your body’s electrical conductivity) for their operation.
While effective, these capacitive switches often face challenges such as reduced sensitivity when the user is wearing gloves or when the switch is in contact with water. Addressing these challenges, TDK built PiezoTap, a high-sensitivity piezoelectric touch switch that aims to offer a more versatile and reliable alternative.
At the core of PiezoTap is the piezoelectric effect phenomenon, which allows it to overcome some of the key limitations of traditional capacitive switches. Specifically, PiezoTap incorporates a piezoelectric pressure detection mechanism that converts the minute displacement caused by touch into an electrical voltage using a piezoelectric element. This alternative approach allows PiezoTap to be operational even in challenging conditions, such as when the user is wearing gloves or in environments where water is present.
The compact and thin design of the PiezoTap allows it to be installed inside a sealed device. This flexibility can find utility in a broader range of applications compared to traditional touch switches.
It is expected to be integrated into wearable devices such as TWS (true wireless stereo) earphones, smart glasses, and smartwatches. Additionally, products used around water, like refrigerators, cooking appliances, washing machines, electric toothbrushes, and bathtub control panels, can benefit from this technology. It also shows promise for use in the automotive sector, particularly in dashboards for cars and other vehicles.
Another demonstration features a spatula with a built-in PiezoTap being moved over a smart pad. The vibration and sound generated will be fed back through a PC to demonstrate the switch’s responsiveness and force feedback capabilities.
PiezoTap is a very interesting option in the field of touch switches. It not only offers a more versatile and reliable alternative to traditional capacitive switches but also expands the possible uses in challenging conditions.