Draft:Implosion fabrication

Implosion Fabrication

Implosion fabrication (ImpFab) is a nanofabrication technique developed by researchers at the Massachusetts Institute of Technology (MIT) in 2018, that allows for the creation of complex three-dimensional (3D) nanostructures by patterning a swollen polymer scaffold with a laser and then shrinking it^[1][2]. This method enables the precise arrangement of various materials, including metals, semiconductors, and biomolecules like DNA, at the nanoscale, by enabling them to be patterned in the swollen state, which is easy to do, followed by isotropic shrinkage, which brings features into nanoscale registration with each other.

Principle

The core principle of implosion fabrication is a reversal of a technique previously developed by the same MIT lab, called expansion microscopy. In expansion microscopy, biological tissues are embedded in a hydrogel and then expanded to allow for higher-resolution imaging. Implosion fabrication takes the opposite approach. First, a highly absorbent polyacrylate hydrogel is used as the initial scaffold, and swollen. Second, a two-photon microscope is used to precisely target specific locations within the expanded hydrogel, for attaching fluorescent handles at certain points. Third, materials are deposited at the sites of the handles. To achieve this, the hydrogel is bathed in a solution containing the materials to be integrated into the structure (e.g., quantum dots, gold nanoparticles, DNA). These materials bind to the handles anchors. Finally, the hydrogel is uniformly shrunk, by dehydration. This dehydration process can reduce the structure's volume by a factor of up to 1,000 (10-fold in each dimension).

Advantages

Unlike many lithography methods that are limited to 2D patterning or require laborious layer-by-layer assembly for 3D structures, ImpFab can create virtually any complex 3D geometry, including non-self-supporting and disconnected structures. It allows for the integration of a wide range of functional materials, including metals, semiconductors, and biomolecules. The technique utilizes equipment commonly found in biology and materials science labs, such as two-photon microscopes, making it more accessible and less costly than traditional nanofabrication facilities. To date, researchers have achieved resolutions in the tens of nanometers.

Already implosion-like procedures have been shown to be useful for making small metallic devices^[3], optical devices^[4], and more. A startup company, Irradiant^[5], is seeking to commercialize such technology

References

1. "Team invents method to shrink objects to the nanoscale". MIT News | Massachusetts Institute of Technology. 2018-12-13. Retrieved 2025-08-02.
2. Oran, Daniel; Rodriques, Samuel G.; Gao, Ruixuan; Asano, Shoh; Skylar-Scott, Mark A.; Chen, Fei; Tillberg, Paul W.; Marblestone, Adam H.; Boyden, Edward S. (2018-12-14). "3D nanofabrication by volumetric deposition and controlled shrinkage of patterned scaffolds". Science. 362 (6420): 1281–1285. Bibcode:2018Sci...362.1281O. doi:10.1126/science.aau5119. PMC 6423357. PMID 30545883.
3. Saccone, Max A.; Gallivan, Rebecca A.; Narita, Kai; Yee, Daryl W.; Greer, Julia R. (December 2022). "Additive manufacturing of micro-architected metals via hydrogel infusion". Nature. 612 (7941): 685–690. Bibcode:2022Natur.612..685S. doi:10.1038/s41586-022-05433-2. ISSN 1476-4687. PMC 9713131. PMID 36265511.
4. Han, Fei; Gu, Songyun; Klimas, Aleks; Zhao, Ni; Zhao, Yongxin; Chen, Shih-Chi (2022-12-23). "Three-dimensional nanofabrication via ultrafast laser patterning and kinetically regulated material assembly". Science. 378 (6626): 1325–1331. Bibcode:2022Sci...378.1325H. doi:10.1126/science.abm8420. PMID 36548430.
5. "Unlocking the potential of light". Irradiant Technologies. Retrieved 2025-08-02.