3D printers help students turn designs such as this one into actual models.

As technology transforms learning in classrooms across the nation, 3D printing, in which three dimensional objects are created through a system that successively layers materials on top one another, is taking hold in classrooms–and is helping to attract more students to technology-rich fields such as engineering.

Modern design uses a technology called CAD, which stands for computer-aided design, to represent 3D objects in a digital file. Today’s CAD software lets users create and draw objects in 3D, and those designs are brought to life via 3D printers.

Companies that manufacture 3D printers for education include Z Corporation, Dimension Printers (a Stratasys brand), and 3D Systems Corp.

A handful of different approaches can create 3D printed objects. One method, developed by 3D printing manufacturer Stratasys, is called fused deposition modeling (FDM). FDM uses a polymer that is heated and deposited by a nozzle, in separate layers, into a pre-made model using an STL file.

Digital light processing (DLP) exposes a liquid polymer to light from a DLP projector, which causes the liquid polymer to harden as a “build plate” shapes the layers. Z Corporation’s ZBuilder Ultra uses this type of system.

Another method uses a printer to spread a thin layer of powder, which is then hardened by a laser to form the bottom layer of the 3D design. Another layer of powder is spread on top of that layer, hardened, and connected to the first layer. This process repeats until the entire model is complete.