Adhesive & Sealant Industry News

3D Printed Stretchable Conductors for Electronics

The printing of conductors has recently arisen as a more eco-friendly, adaptable and economical substitute for conventional production methods, as materials are only placed where they are required, reducing wastage. Additionally, printing allows for the mass fabrication of mechanically bending and stretching-tolerant flexible electronics. Adhesive materials are often incorporated for bonding properties. Conductivity of stretchable materials remains constant even when subjected to substantial deformation; this property is known as high dynamic stability. This makes it easier to produce wearable electronics, which have promising uses in fields as diverse as medicine and athletics.

What materials can be used to make printed stretchable conductors?

  • There are a number of different materials that can be used to make printed stretchable conductors. Some of the most common materials include:
  • Metal nanoparticles: These nanoparticles are often made of silver, gold or copper. They are highly conductive, but they can be expensive and difficult to process.
  • Carbon nanotubes: Carbon nanotubes are very strong and conductive, but they can be difficult to disperse evenly in a printable ink.
  • Graphene: Graphene is a one-atom-thick sheet of carbon atoms that is highly conductive and stretchable. However, it is also very expensive to produce.
  • Liquid metals: Liquid metals, such as gallium-indium alloys, are highly conductive and can be easily injected into printed structures. These can be difficult to encapsulate and can corrode other materials.

The choice of material will depend on the specific application. For example, if a high level of conductivity is required, then metal nanoparticles may be the best choice. However, if cost is a concern, then carbon nanotubes may be a better option.

How printed stretchable conductors are produced

Printed stretchable conductors can be made using various methods, such as inkjet printing, screen printing and 3D printing, which often incorporate adhesives for creating a bonded yet stretchable application.

Common Considerations

In some cases, a post-printing heat treatment (sintering) might be necessary. This helps improve the electrical conductivity of the printed traces by fusing the conductive particles together. However, it’s crucial to ensure the sintering temperature doesn’t damage the stretchable properties of the conductor. Moreover, all these methods require using flexible substrates that are compatible with the printing process and the intended application. Common choices include polymers like PET (polyethylene terephthalate) or PDMS (polydimethylsiloxane).

Advantages of printed stretchable conductors

There are several advantages to using printed stretchable conductors. First, they can be fabricated quickly and easily using a variety of printing techniques. This makes them well-suited for rapid prototyping and low-volume production. Second, they can be conformal, meaning that they can conform to the shape of the substrate on which they are printed. This makes them ideal for use on curved or uneven surfaces. Third, they are lightweight and flexible, which makes them comfortable to wear and less likely to break.

Source: Globalspec