What is High Area Rapid Printing (HARP) Technology?

Physician David Walker models one of the face shields printed using the LAKE printer. (Credit: Northwestern University)

In 2019, researchers at Northwestern University unveiled a new type of 3D printer capable of dramatically faster production speeds without sacrificing quality or resolution, which is a typical problem when attempting to 3D print with large equipment. Northwestern’s Mirkin Group, led by Dr. Chad Mirkin, set out to improve stereolithography printing methods to make it more likely that warehouses and manufacturers can one day transition away from creating their tools and parts with injection molds and fully embrace 3D printing. For that to happen, printers will need to be fast enough to produce parts on demand. High Area Rapid Printing (HARP) just might be the technology that makes this a reality.

What Is HARP Technology and How Does It Work?

High area rapid printing technology is a subset of additive manufacturing or 3D printing that permits continuous, high-throughput printing of large objects at rapid speeds. Compared to traditional methods of 3D printing, HARP is much faster and more efficient, capable of printing objects the size of an average adult in several hours. HARP is an improvement on older methods of stereolithography where many layers of resin are put down by a printer to create an object. Essentially, it is a process of converting liquid plastic into hardened objects.

Azul 3D’s technology works by passing a constant stream of fluid across the printing interface to keep the printer from overheating, allowing it to print much faster than typical 3D printers. (Credit: Azul 3D)

Non-HARP 3D printers are limited by the heat they produce when running at fast speeds. Surface temperatures can top 180 degrees C, which is dangerously hot and can lead to parts cracking or deforming. 3D printers just can’t reach their top speeds without generating intense amounts of heat. HARP technology aims to alleviate this problem by working with a non-stick liquid that is similar to Teflon.

In HARP printers, the non-stick liquid circulates below the resin to reduce heat and cool the system. Light is projected through the system to rapidly harden the resin. The entire interface is non-stick, which removes the need to repeatedly cleave parts from the bottom of the print vat. This allows the printer to work at high speeds without suffering a drop in quality, even when printing large structures. Traditional 3D printers are not even capable of printing small parts at rapid speeds without facing quality issues.

The primary benefit of HARP is that it improves printing speeds up to a hundredfold, making it practical to ditch on-hand inventory in favor of on-demand printed parts and tools. Because HARP is not limited in the size of surfaces and shapes it can print, a HARP printer could potentially be used to create something as large as an airplane wing or turbine blade all the way down to a tiny medical device. Compared to established leaders in the 3D printing sector, HARP boasts 2000x throughput based on estimated 20x scale and 100x speed with more flexibility in the type of resin selected.

The technology is currently being commercialized and developed by Azul 3D, a startup company led by the researchers that was recently named a Formnext Start-up Challenge winner for 2021.

“Our technology helps manufacturers consolidate parts, create new geometries, secure a digital inventory, support localized manufacturing, and design completely customizable products. Our printers will represent a new paradigm in the industry. We will be the go-to solution for manufacturers of industrial, consumer and automotive goods,” said Azul 3D CEO Cody Peterson. “Azul 3D will fill the gap between traditional additive manufacturing (prototyping, molds & tooling, and limited production runs) and traditional mass manufacturing of plastic goods. Our technology and product portfolio fill this unmet need in today’s manufacturing ecosystem.”

How Can HARP Be Used?

At the height of the COVID-19 pandemic, the need for personal protective equipment for frontline medical workers spiked and could not be sourced quickly enough to keep up with the exploding health crisis. In this moment, the team at Azul 3D stepped up to put their printers to work cranking out masks, face shields and goggles. Azul was able to top 1,000 shields per day using a 13-foot tall HARP printer that ran 24/7. In an effort to do their part to tackle the challenge of the pandemic, Azul sped up the production of their beta printers and shipped over 10,000 shields, many of which were sent to the Navajo Nation as it suffered one of the worst COVID outbreaks in America.

“Even fleets of 3D printers were having difficulty meeting demand for face shields because the need was so enormous. But HARP is so fast and powerful that we could put a meaningful dent in that demand,” said Mirkin.

Producing thousands of face shields per week would not have been possible with standard 3D printers, which shows the power and value in unlocking HARP for mass production of other everyday items. The true value in 3D printing lies in eliminating mold-injected production for tools, which required workers with specialized skills and offer minimal economies of scale because the tools are often produced in small quantities and are single use. HARP technology could be applied to manufacturing everything from small tools and custom parts to massive wind turbine blades.

“3D printing is conceptually powerful but has been limited practically,” said Mirkin, who led the product’s development. “If we could print fast without limitations on materials and size, we could revolutionize manufacturing. HARP is poised to do that.”

Commercializing the Technology and What Comes Next

The research team at Northwestern that pioneered HARP has spun out the technology into a commercial venture led by Dr. Chad Mirkin. The resulting company, Azul 3D, has already begun taking orders on its first product, the LAKE 3D printer. In addition to designing and producing printing hardware, Azul also has a chemistry group that is working on designing their own proprietary blends of resins that work specifically with HARP printing.

The LAKE printer is Azul 3D’s first commercial product, and the company is currently taking orders for their flagship printer that will unlock HARP technology for the manufacturing industry. (Credit: Azul 3D)

“Our technology fills the fundamental gap in today’s market between prototyping and injection molding. Filling this gap comes from leveraging additive manufacturing’s inherent advantages while offering our customers the throughput, economics, part quality, and material diversity that is enabled through traditional manufacturing,” Peterson explained. “We believe the new geometries that additive manufacturing enables must be paired with bespoke materials to create a product that is ready for industrial and consumer use. We create completely customizable polymers that can be as flexible, rigid, soft, or strong as needed, and can be formulated to match exact colors and hues. We are excited to show the world our innovations in materials.”

Azul 3D’s next steps  in commercializing and generating revenue from their technology is to market and sell the LAKE 3D printer and form partnerships with major players in the manufacturing and consumer goods sectors. The company is already making strides to showcase their abilities by partnering with recognizable brands like Wilson Sporting Goods to design pickleball paddles and DuPont on electronics materials.

“We partner with companies as a full-stack solution, from material selection and design through implementation in their factories,” said Azul 3D CEO Cody Petersen. “With Wilson, we not only collaborated to make a better pickleball paddle—we were able to entirely rethink how the paddle is designed, thanks to our materials and technology.”

Azul is a very new player on the 3D printing scene, but its powerful technology has the potential to completely revolutionize both small mom and pop shops producing tools and massive corporate manufacturing floors turning out much larger items. If the company’s star-studded lineup of industry leaders are able to execute and effectively showcase the power of their technology and printers, there’s little reason to think they won’t live up to their slogan, “Your future factory is here!”