First Soft Touchpad That Senses Contact Without Electricity Developed

Researchers at Tampere University have unveiled the world’s first soft touchpad capable of sensing force, area, and location of contact without the need for electricity. This breakthrough technology uses pneumatic channels instead of traditional electronic sensors, making it suitable for environments such as MRI machines and other settings where electronic devices are not viable. Additionally, this technology could be used in soft robots and rehabilitation aids.

The touchpad is made entirely of soft silicone and features 32 pneumatic channels that adapt to touch. Each channel is just a few hundred micrometers wide. The device is not only capable of detecting the force, area, and location of touch but is also precise enough to recognize handwritten letters and distinguish multiple simultaneous touches.

"Electronic sensors often fail in extreme conditions, like strong magnetic fields. Since this touchpad is non-electric, it remains unaffected by magnetic fields, making it ideal for use in MRI machines," explains Doctoral Researcher Vilma Lampinen.

This innovative sensor technology could be used in situations where a pneumatic robot, guided by the touchpad data alongside MRI scans, might take a biopsy while a patient is still undergoing an MRI scan. The touchpad’s ability to function in environments with strong radiation or where sparks from electricity pose a danger further highlights its potential in hazardous conditions.

The flexible silicone material of the touchpad enables its integration into devices that require a non-electrical touch sensing solution, such as soft robots, which are typically powered by pneumatic mechanisms. Adding this sensing capability to soft, non-electric devices opens possibilities for mapping touch information across the device's surface, which could benefit applications in advanced prosthetics and soft robotic hands.

“Soft robotic hands could replace current prosthetic hands, especially in applications like production lines. They are safer, lighter, and potentially cheaper to manufacture. Additionally, touch sensors would allow for more delicate gripping,” says Lampinen.

The touchpad’s design also holds promise for wearable devices, particularly in rehabilitation. Soft, comfortable materials can offer a significant advantage over traditional hard devices, improving comfort while still enabling precise sensing capabilities.