All Publications

  • Methods for modeling and real-time visualization of CLIP and iCLIP-based 3D printing GIANT Lipkowitz, G., Coates, I., Krishna, N., Shaqfeh, E. G., DeSimone, J. M. 2024; 17
  • Printing atom-efficiently: faster fabrication of farther unsupported overhangs by fluid dynamics simulation Lipkowitz, G., Krishna, N., Coates, I., Shaqfeh, E. G., DeSimone, J. M., Spencer, S. N. ASSOC COMPUTING MACHINERY. 2023
  • Single-digit-micrometer-resolution continuous liquid interface production. Science advances Hsiao, K., Lee, B. J., Samuelsen, T., Lipkowitz, G., Kronenfeld, J. M., Ilyn, D., Shih, A., Dulay, M. T., Tate, L., Shaqfeh, E. S., DeSimone, J. M. 2022; 8 (46): eabq2846


    To date, a compromise between resolution and print speed has rendered most high-resolution additive manufacturing technologies unscalable with limited applications. By combining a reduction lens optics system for single-digit-micrometer resolution, an in-line camera system for contrast-based sharpness optimization, and continuous liquid interface production (CLIP) technology for high scalability, we introduce a single-digit-micrometer-resolution CLIP-based 3D printer that can create millimeter-scale 3D prints with single-digit-micrometer-resolution features in just a few minutes. A simulation model is developed in parallel to probe the fundamental governing principles in optics, chemical kinetics, and mass transport in the 3D printing process. A print strategy with tunable parameters informed by the simulation model is adopted to achieve both the optimal resolution and the maximum print speed. Together, the high-resolution 3D CLIP printer has opened the door to various applications including, but not limited to, biomedical, MEMS, and microelectronics.

    View details for DOI 10.1126/sciadv.abq2846

    View details for PubMedID 36383664

  • Injection continuous liquid interface production of 3D objects. Science advances Lipkowitz, G., Samuelsen, T., Hsiao, K., Lee, B., Dulay, M. T., Coates, I., Lin, H., Pan, W., Toth, G., Tate, L., Shaqfeh, E. S., DeSimone, J. M. 2022; 8 (39): eabq3917


    In additive manufacturing, it is imperative to increase print speeds, use higher-viscosity resins, and print with multiple different resins simultaneously. To this end, we introduce a previously unexplored ultraviolet-based photopolymerization three-dimensional printing process. The method exploits a continuous liquid interface-the dead zone-mechanically fed with resin at elevated pressures through microfluidic channels dynamically created and integral to the growing part. Through this mass transport control, injection continuous liquid interface production, or iCLIP, can accelerate printing speeds to 5- to 10-fold over current methods such as CLIP, can use resins an order of magnitude more viscous than CLIP, and can readily pattern a single heterogeneous object with different resins in all Cartesian coordinates. We characterize the process parameters governing iCLIP and demonstrate use cases for rapidly printing carbon nanotube-filled composites, multimaterial features with length scales spanning several orders of magnitude, and lattices with tunable moduli and energy absorption.

    View details for DOI 10.1126/sciadv.abq3917

    View details for PubMedID 36170357

  • Characterization of a 30 m pixel size CLIP-based 3D printer and its enhancement through dynamic printing optimization. Additive manufacturing Lee, B. J., Hsiao, K., Lipkowitz, G., Samuelsen, T., Tate, L., DeSimone, J. M. 2022; 55


    Resolving microscopic and complex 3D polymeric structures while maintaining high print speeds in additive manufacturing has been challenging. To achieve print precision at micrometer length scales for polymeric materials, most 3D printing technologies utilize the serial voxel printing approach that has a relatively slow print speed. Here, a 30-m-resolution continuous liquid interface production (CLIP)-based 3D printing system for printing polymeric microstructures is described. This technology combines the high-resolution from projection microstereolithography and the fast print speed from CLIP, thereby achieving micrometer print resolution at x103 times faster than other high-resolution 3D printing technologies. Print resolutions in both lateral and vertical directions were characterized, and the printability of minimum 30 m features in 2D and 3D has been demonstrated. Through dynamic printing optimization, a method that varies the print parameters (e.g. exposure time, UV intensity, and dark time) for each print layer, overhanging struts at various thicknesses spanning 1 order of magnitude (25 m - 200 m) in a single print are resolvable. Taken together, this work illustrates that the micro-CLIP 3D printing technology, in combination with dynamic printing optimization, has the high resolution needed to enable manufacturing of exquisitely detailed and gradient 3D structures, such as terraced microneedle arrays and micro-lattice structures, while maintaining high print speeds.

    View details for DOI 10.1016/j.addma.2022.102800

    View details for PubMedID 35602181

  • Numerical Modelling of Moisture Loss during Controlled Drying of Marine Archaeological Wood FORESTS Lipkowitz, G., Hennum, K., Piva, E., Schofield, E. 2021; 12 (12)

    View details for DOI 10.3390/f12121662

    View details for Web of Science ID 000737528300001