This grant supports research that will contribute new knowledge related to an additive manufacturing process, promoting both the progress of science and advancing national prosperity. Additive manufacturing, often called 3D printing, plays a pivotal role in the rapid design and fabrication of technological devices without the need for expensive tooling and long turnaround times. However, high-performance 3D printing of functional devices, such as energy-absorbing materials, wearable electronics, and morphing structures, remains a major challenge. Such limitations in performance are largely attributed to the difficulty in extruding highly functional inks and actively controlling their properties. This award supports fundamental research to provide knowledge for developing a 3D printing process that extrudes high-performance inks with tunable properties. The new printing technology will improve the performance of current 3D-printed devices and unlock new designs in material fabrication, bio-manufacturing, and customizable electronic production. Therefore, results from this research will greatly benefit the U.S. economy and society. This research involves multiple disciplines including fluid mechanics, microfabrication, and materials science. This transdisciplinary approach will help broaden participation of underrepresented groups in research and promote equity and inclusion in engineering education.
Functional inks in 3D printing are often extremely viscous due to the required high filler content, and they often exhibit shear jamming that leads to catastrophic nozzle clogging. Moreover, the inability to alter ink properties, such as rigidity, conductivity, and thermal response, constrains manufacturing and thus inhibits the potential of realizing many new designs. To address such a challenge, this research will develop an understanding of and strategies for controlling functional ink properties via ultrasonic acoustic fields during extrusion. The hypothesis builds upon recent advances in thickening suspensions, in which high-frequency perturbations can be used to manipulate the microstructure of viscous fluids and substantially reduce their flow resistance. Specifically, this project will investigate the relationship between the mechanical properties of a particle-based model ink and the ink?s acoustically altered microstructure. The integration of these findings will lead to the development of design principles and perturbation protocols for building printing platforms. The project will explore two perturbation approaches: first, the simple attachment of a piezoelectric to a printing nozzle, and second, the engineering of an acoustic patterning device that precisely controls the ink microstructure. Collectively, these experiments will provide a foundation for developing active control of ink properties for printing functional devices.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
