Toward A 3D Metamorphic Touchpad

The touchpad is one of the most commonly used human-machine interfaces that is being used by people all over the world in their daily lives. There are different approaches to realize touch-sensitive devices that fundamentally vary in their operating mechanisms.

However, mechanically, most of these devices are rigid and limited to certain predefined shapes, which will no longer be sufficient for users in the future. In the future, electronic devices will be user-friendly; not only in their software but also in their hardware, which means the user could be able to change the 3D shape of their devices at will. These emerging shape-adaptive electronic devices are introduced as Metamorphic Electronics.

What are“Metamorphic Electronics”? The concept is borrowed from nature: metamorphosis, which is a very common phenomenon. This is a biological process by which an animal physically develops after birth or hatching by cell growth and differentiation. To give an example, a butterfly starts its life from an egg, then to larva to pupa, and finally to an adult. An animal appears very differently and functions differently through its metamorphosis processes.

Metamorphic electronics follows a similar paradigm: these electronic devices can be
geometrically deformed by different manners and might function differently. Metamorphic electronics are the electronics or electronic systems which are stretchable and deformable and which morph to adapt to a new topology and form factor.

A nanotechnology research group from the Technische Universität Ilmenau, Germany, recently demonstrated few metamorphic electronic devices including a metamorphic lighting panel and metamorphic microphone arrays. The same group has recently
published an article in Advanced Materials Technologies demonstrating metamorphic
touchpad, a stretchable touchpad that can morph from a planar to a hemispherical shape. The group used two stretchable metal layers separated by a dielectric layer in a stretchable silicone matrix to realize the capacitive touchpad. The design was inspired by a commercial touchpad.

The method used to produce the metamorphic touchpad is fully compatible with conventional printed circuit board technology. Researchers demonstrated that a touchpad in a rubber matrix could be formed into different shapes without altering its functionality noticeably since the device is stretchable. For example, the planar
metamorphic touchpad can be connected to a computer via USB connection can track the finger movement through the cursor’s position. The same touchpad can be inflated using air to form a hemisphere and remains functional. More complex geometrical shapes can be envisioned.

The potential applications of the demonstrated metamorphic touchpad are enormous. The 3D shape deformation mechanism of the planar touchpad can be used to realize a true 3D touchpad that would revolutionize current human-machine interfaces for virtual reality, gaming, or 3D design. Moreover, the conformal property of the stretchable touchpad would allow to wrap around complex 3D shapes or human body as a wearable device. Other potential applications range from material to medical diagnostics, robotics, haptics, automotive, and sensing.

The future of metamorphic electronics is enormous. Fully developed, any electronic product known today may take on new 3D shapes and interesting form factors in the future. However, the field is young, and there is plenty of room for discoveries, development, and new architectures.