High‐Resolution 3D Printing of Freeform, Transparent Displays in Ambient Air

Direct 3D printing technologies to produce 3D optoelectronic architectures have been explored extensively over the last several years. Although commercially available 3D printing techniques are useful for many applications, their limits in printable materials, printing resolutions, or processing temperatures are significant challenges for structural optoelectronics in achieving fully 3D‐printed devices on 3D mechanical frames. Herein, the production of active optoelectronic devices with various form factors using a hybrid 3D printing process in ambient air is reported. This hybrid 3D printing system, which combines digital light processing for printing 3D mechanical architectures and a successive electrohydrodynamic jet for directly printing transparent pixels of organic light‐emitting diodes at room temperature, can create high‐resolution, transparent displays embedded inside arbitrarily shaped, 3D architectures in air. Also, the demonstration of a 3D‐printed, eyeglass‐type display for a wireless, augmented reality system is an example of another application. These results represent substantial progress in the development of next‐generation, freeform optoelectronics. A hybrid, 3D printing system based on digital light processing and an electrohydrodynamic inkjet is developed for producing freeform optoelectronic devices in ambient air. This 3D printing system can print all components of the device as well as the mechanical frames; thus, the system can produce transparent 3D architectures with arbitrary shapes at the desired locations.