Our primary research interests focus on advancing additive manufacturing technology (3D printing), particularly at the micro and nanoscale. Our work involves using light to achieve high-speed, high-precision 3D printing. One of our notable innovations includes a technique that allows the dynamic manipulation of each printed layer during the process, using light and a robotic arm. This enables the creation of complex structures with enhanced flexibility, efficiency, and geometric complexity, far surpassing traditional 3D printing methods.

Our work in additive manufacturing, allows the printing of intricate objects, such as soft robotic grippers and customized biomedical devices like vascular stents. The method has potential applications in both additive and traditional subtractive manufacturing, paving the way for hybrid processes in the future​.

News Stories: Northwestern Now, McCormick News 

Selected publications:

• Huang, Jigang, Henry Oliver T. Ware, Rihan Hai, Guangbin Shao, and Cheng Sun. “Conformal geometry and multimaterial additive manufacturing through freeform transformation of building layers.” Advanced Materials 33, no. 11 (2021): 2005672. (Link)
• Shao, Guangbin, Henry Oliver T. Ware, Longqiu Li, and Cheng Sun. “Rapid 3D printing magnetically active microstructures with high solid loading.” Advanced Engineering Materials 22, no. 3 (2020): 1900911. (Link)

This research is part of a broader initiative in regenerative engineering aimed at developing bioresorbable medical devices that perform essential functions and naturally degrade within the body. This eliminates the need for follow-up surgeries and minimizes long-term complications. In collaboration with Professor Ameer and the Center for Advanced Regenerative Engineering (CARE), we are working on a variety of bioresorbable devices that promote wound healing and tissue regeneration.

One example is the bioresorbable vascular scaffolds (BVSs), designed to dissolve after their role is complete, significantly reducing risks such as clot formation or inflammation, which are common with traditional metal stents. By utilizing our cutting-edge 3D printing technology, we can create these scaffolds with ultrathin struts—thinner than a human hair—leading to improved performance over earlier versions of bioresorbable stents. These BVSs are also capable of releasing drugs like Everolimus, which helps prevent the re-narrowing of vessels following angioplasty.

Other applications we are currently working on include:

• Citrate-based craniofacial scaffolds for bone tissue engineering
• Electrically conductive hydrogels for nerve regeneration
• Bioresorbable flow diverter for brain aneurysms
  

News Stories: McCormick News 

Selected publications:

• Ding, Yonghui, Liam Warlick, Mian Chen, Eden Taddese, Caralyn Collins, Rao Fu, Chongwen Duan et al. “3D-printed, citrate-based bioresorbable vascular scaffolds for coronary artery angioplasty.” Bioactive Materials 38 (2024): 195-206. (Link)
• Ding, Yonghui, Rao Fu, Caralyn Paige Collins, Sarah‐Fatime Yoda, Cheng Sun, and Guillermo A. Ameer. “3D‐Printed radiopaque bioresorbable stents to improve device visualization.” Advanced healthcare materials 11, no. 23 (2022): 2201955. (Link)
• Tropp, Joshua, Caralyn P. Collins, Xinran Xie, Rachel E. Daso, Abijeet Singh Mehta, Shiv P. Patel, Manideep M. Reddy, Sophia E. Levin, Cheng Sun, and Jonathan Rivnay. “Conducting polymer nanoparticles with intrinsic aqueous dispersibility for conductive hydrogels.” Advanced Materials 36, no. 1 (2024): 2306691. (Link)

Crimping 3D printed BVS for packaging into the balloon catheter.

Our biomedical imaging research advances cutting-edge technologies that push the limits of optical resolution, depth, and sensitivity, with applications ranging from structural to functional imaging. A major focus is the development of optical micro-ring resonators (MRRs) made from compressible polymer materials, which serve as ultra-sensitive ultrasonic detectors for photoacoustic imaging. It extends the ability to visualize deep tissues, surpassing the optical diffusion limit.

In addition to photoacoustic imaging, our work includes the development of super-resolution microscopy. By utilizing spectroscopic methods and single molecule localization techniques, we achieve unprecedented levels of optical precision, allowing for imaging at the nanoscale. This work has been crucial for studying chromatin remodeling and other molecular processes that require high-resolution imaging for better diagnostic and therapeutic outcomes.

Moreover, we are pioneering the use of 3D printing to create miniaturized, low-cost imaging systems, such as disposable optical microscopes. These devices can be rapidly produced at a fraction of the cost of conventional microscopes, making them highly accessible for applications in resource-limited environments, such as field diagnostics and disposable medical devices. This innovation ensures broad access to advanced imaging technologies for scientific, medical, and educational use.

News Stories: Nature, McCormick News on 3D print optics, McCormick News on Super-resolution imaging, McCormick News on Photoacoustic Imaging

Selected publications:

• Hai, Rihan, Guangbin Shao, Henry Oliver T. Ware, Evan Hunter Jones, and Cheng Sun. “3D Printing a Low‐Cost Miniature Accommodating Optical Microscope.” Advanced Materials 35, no. 20 (2023): 2208365. (Link)
• Li, Hao, Biqin Dong, Xian Zhang, Xiao Shu, Xiangfan Chen, Rihan Hai, David A. Czaplewski, Hao F. Zhang, and Cheng Sun. “Disposable ultrasound-sensing chronic cranial window by soft nanoimprinting lithography.” Nature communications10, no. 1 (2019): 4277. (Link)
• Song, Ki-Hee, Yang Zhang, Benjamin Brenner, Cheng Sun, and Hao F. Zhang. “Symmetrically dispersed spectroscopic single-molecule localization microscopy.” Light: Science & Applications 9, no. 1 (2020): 92. (Link)