How Are Conductive Inks Made?

Conductive inks are pivotal in advancing printed electronics, enabling the production of flexible circuits, sensors, and biosensors across various applications. Inkjet printing is a commonly used method for producing these inks, where conductive particles are precisely deposited on substrates to form functional, conductive patterns. However, choosing the right ink and printing technique is crucial, as different applications have specific functional requirements.

The Inkjet Printing Process and Key Material Choices

Inkjet printing offers several advantages in conductive ink manufacturing, including a simplified process, reduced material waste, and adaptability to various surfaces. During the printing process, ink is stored in cartridges and ejected through fine nozzles to form conductive patterns. The success of the inkjet method is determined largely by the choice of material, with silver nanoparticles being a popular option due to their high electrical conductivity, thermal stability, and relatively low cost. Additionally, silver nanoparticles are low-melting, which allows them to form conductive films at lower temperatures, essential for applications using flexible substrates like polymers and paper.

The Challenges of Conductive Ink Printing

In the world of printed electronics, selecting a printing process is crucial, as each process is suited to specific functional requirements. The choice often depends on balancing cost and performance for each application. Ink formulation must consider key factors like viscosity and surface tension, as well as compatibility with the substrate and printing technique. For example, in the rotary screen printing  method known for handling higher-viscosity inks, considerations like ink drying time, substrate temperature limits, and printed layer thickness are essential.

A critical challenge is the trade-off between curing time and temperature. As conductive inks often need to be printed on plastic films or polymers, high temperatures are not always feasible, slowing down the curing process and increasing production time. This makes it essential to optimize each parameter of the process to meet both performance and manufacturing efficiency goals.Companies like ad-nano technologies are working efficiently towards conductive ink quality and greater applications.

Conductive Ink Composition and Sintering

After printing, the matrix volume must be reduced to establish conductive pathways, often achieved through a curing or sintering process. There are various sintering techniques thermal, chemical, electric, and laser all of which affect production costs and time. Some substrates, like those used in Kodak and Epson photo papers, come pre-coated with cationic polymers that allow for spontaneous particle sintering, potentially reducing costs by eliminating additional post-processing.

Compatibility Between Ink and Screen Printing Techniques

In screen printing, the compatibility between conductive ink and screen type is essential to achieving desired results. Factors like particle size, ink deposition, resolution, and viscosity must be carefully matched to the screen type. Conductive inks typically use metals like silver or carbon, often combined with a conductive polymer and solvent. The ink passes through electroformed nickel screens, allowing it to form conductive tracks once deposited.

Applications in Biosensors and Printed Electronics

Conductive inks are widely used in printed electronics, particularly for flexible biosensors, where electrodes are printed onto substrates and configured with microfluidic channels for biological testing. Such sensors can analyze the electrical properties of biological samples, providing insights through changes in conductivity or impedance. These applications highlight the role of conductive inks in advancing technologies across healthcare, electronics, and communication.

Conclusion:

Conductive inks are made by combining conductive materials, such as graphene,silver or carbon, with a liquid carrier and additives. These inks are used in various applications, including printed electronics, sensors, and energy storage devices. The recent advancements in conductive ink technology have led to increased interest and adoption in industries like automotive, healthcare, and consumer electronics. Conductive inks play a crucial role in enabling flexible and wearable electronics, as well as the development of smart devices.

For more info:-  

Conductive inks globally

Graphene conductive Ink Manufacturer

Silver Conductive Ink/paste Supplier