Photo credit: www.sciencedaily.com

Revolutionizing 3D Printing: Beckman Researchers Introduce Growth Printing

In a striking advance for 3D printing technology, researchers at the Beckman Institute for Advanced Science and Technology have developed a groundbreaking method that significantly enhances manufacturing speed and efficiency. Their innovative approach, termed “growth printing,” draws inspiration from the natural expansion of tree trunks, allowing for the rapid production of polymer parts without the need for traditional molds and expensive machinery.

This new technique has been detailed in the journal Advanced Materials, showcasing a shift in 3D printing that could revolutionize the field. Sameh Tawfick, a professor at the University of Illinois Urbana-Champaign and the project’s lead, expressed enthusiasm for the innovation, noting the challenge and excitement of discovering novel manufacturing processes.

Tawfick explained that while injection molding has been the conventional method for mass-producing items from polymers, the associated costs and complexity—especially when it comes to maintaining molds and curing ovens—pose significant barriers. Additive manufacturing, in contrast, simplifies production, making it well-suited for creating custom items like prosthetics. However, additive 3D printing often faces hurdles such as slow speed and high expenses, prompting their team’s desire to enhance efficiency without compromising quality.

The growth printing technique employs a unique method where amber-colored liquid resin, known as dicyclopentadiene (DCPD), is placed in a cooled glass container. By applying heat to a specific point in the resin, the resulting reaction expands outward at an impressive rate of 1 millimeter per second—far exceeding the speed of desktop 3D printers and even surpassing some of the fastest natural growth rates observed, like that of bamboo. This process, termed frontal ring-opening metathesis polymerization (FROMP), efficiently transforms the liquid resin into a solid polymer known as poly-dicyclopentadiene (p-DCPD).

As the solid sphere expands, the researchers can manipulate its shape by adjusting its position in the resin, which allows for intricate design possibilities. For example, to achieve a wavy edge, they can lift the resin and hold it still to create a unique contour.

The design philosophy behind this innovation draws heavily from the natural world. Tawfick noted how trees exhibit varied growth patterns influenced by environmental factors such as gravity and sunlight, leading to unique structural adaptations. This fascination with morphogenesis, the biological process that causes organisms to develop their shape, was further fueled by Tawfick’s early influences, including D’Arcy Wentworth Thompson’s seminal work, “On Growth and Form.”

Using the new growth printing technique, the research team successfully crafted several axisymmetrical objects, such as a pinecone and a raspberry. While creating these shapes presented challenges, the researchers also demonstrated the ability to produce non-symmetrical forms, including a kiwi bird with a defined head and beak, showcasing the method’s versatility.

Philippe Geubelle, a co-author and Illinois professor of aerospace engineering, emphasized the remarkable efficiency of the growth-printing method. The development of computational tools alongside the physical process allowed the team to predict and control the motion of the solid material effectively, contributing to the creation of targeted shapes.

Despite its promise, growth printing is not without limitations. Tawfick acknowledged that while creating complex, curved structures is theoretically possible, programming these shapes presents significant mathematical challenges. This reflects a broader theme within nature, where perfect geometric forms are uncommon.

Looking to the future, Tawfick envisions the potential for applying this method to larger-scale polymer products, such as wind turbine blades. The project received funding from the U.S. Department of Energy’s Office of Science Basic Energy Sciences program, which aims to advance transformative manufacturing technologies.

Student Yun Seong Kim, the first author of the study, remarked on the collaborative spirit that underpinned the project, highlighting the diverse expertise that came together to achieve this innovation.

Coauthor Randy Ewoldt, holding the Alexander Rankin Professorship in Mechanical Science and Engineering, also praised the collaboration, attributing the project’s success to a culture of teamwork and academic excellence within the Illinois research community.

Source
www.sciencedaily.com