As everyone from defense contractors to hobby enthusiasts explore the possibilities of additive manufacturing (AM) technology (popularly known as 3D printing), the question must be asked: with its seemingly endless applications, is it the answer to all things manufacturing related? Is it truly a panacea, or "just another tool in our manufacturing toolbox," as Tim Caffrey, an associate with Wohler Associates, suggests?
It's been called the start of the next Industrial Revolution. Successful uses of AM have been evolving for more than 25 years and have led to the creation of a wide range of manufactured products, from dental implants and artificial limbs to airplane wings and car parts. President Barack Obama, in his State of the Union address this past February, noted its potential impact. Much recent press, including last week's announcement of the Stratasys-Makerbot merger, makes the future of AM difficult to ignore, as its uses grow exponentially. A recent IDTechEx report says the market will be worth $4 billion by 2025.
AM has the potential to allow many other leading-edge technologies to enter the marketplace more quickly and efficiently. Consider smart packaging. These packaging systems allow product manufacturers to track and trace goods, control temperature, monitor freshness, and ensure a product's safety or authenticity. Other times, they offer interactive gimmicks, such as Heineken's "Ignite" bottles. An unrelated IDTechEx report shows revenue from smart packaging growing to $1.45 billion in 2023.
Integral to smart packaging is radio frequency identification (RFID) electronics, which help transform the interaction between the package and the user. Currently, the smart packaging manufacturing process utilizes existing 2D technologies to print circuits, such as high-quality screen and inkjet printing.
However, these 2D technologies often either slow down the in-line production process or require offline printing and later incorporation into the smart packaging. With five basic components -- sensor, logic, radio, antenna, and power -- printed circuitry is seen as one of the major roadblocks to RFID-enabled and other forms of smart or active packaging. With the limitations of 2D printing technologies used for RFID circuitry, could AM be used profitably and effectively to manufacture circuits directly onto a package?
For the near future, the answer seems to be "no." The potential uses of AM for RFID in industries such as smart packaging are limited by the constraints of AM itself, which include speed, material requirements, and cost, according to Dr. Wendy Kneissl, senior technology analyst for IDTechEx.
Current AM processes for manufacturing circuits are even slower and more energy intensive than existing 2D circuit manufacturing processes. A 3D printer that lays the conductive lines needed for circuitry can manufacture up to 30,000 items a week. Kneissl calls 30,000 an aspirational number and says the manufacturing needs in smart packaging are much higher, typically into the billions.
AM requires circuits to be printed onto temperature-resistant materials such as high-grade engineering plastics. This process uses specialty inks such as nanoparticle silver. According to Kneissl, any other materials would be destroyed by the lasers used in AM. Conversely, 2D RFID printing works with simple substrates such as paper and can utilize common, silicon-based inks.
Industrial AM remains expensive. "The machines cost around $1 million each," says Kneissl, and that doesn't include the costs associated with running the lasers and purchasing materials such as the substrates, inks, etc. Printing RFID using conventional 2D printing techniques continues to be more cost effective. Economies of scale apply to AM, but not in the same way they apply to conventional manufacturing and printing. AM, with its expensive equipment, materials, labor, etc, increases the per-unit costs and decrease its financial viability.
"The primary thrust currently," says Kneissl, "is in the aerospace sector, where the ability to 3D print circuitry, for example, directly onto a parabolic wing, simplifies the electronics, leads to lower maintenance and fewer failures, streamlines the manufacturing, and also frees up space for extra payload."
Aerospace is high-value manufacturing, not high-volume, which is what is required for the cost-effective manufacturing of RFID circuits. Kneissl feels the primary advantage of AM with regard to manufacturing circuitry is its ability to print on 3D surfaces. But "this is not required to add functionality of the type implied by the term 'smart packaging,'" she admitted, adding that she doesn't believe AM will ever compete with printed, or non-printed, RFID.
The current state of AM technology does not appear to be able to overcome the hurdles that exist at the intersection of smart packaging and RFID. But, the Industrial Revolution occurred over 60 to 80 years, so industry may just have to wait to see if AM is truly the next revolution, and if it can conquer the challenges such as those presented with printing RFID.