Revealing the Nano-Mechanical Properties of DNA-Templated Lattices

Phonons, the collective vibrational modes of atoms or particles, are the fundamental excitations that govern a material’s thermal, electrical, and optical properties. Understanding how phonons arise and behave in three-dimensional nanostructures is key for intentionally designing novel materials with tailored properties. We leverage the programmability of DNA origami to design frames that self-assemble into nanostructures with precisely defined symmetries, lattice spacing, and material composition. By creating intricate 3D DNA lattices of various nanoparticles and templating them with inorganics, we formed nanoscale inorganic frameworks of different symmetries, providing a platform for studying the collective dynamics of these nanostructures.

By analyzing the positions and fluctuations of these nanoparticles, we can extract information about the lattice vibrational and phonon-polariton modes within the assemblies. Specifically, we employ hard X-ray tomography (HXT) to capture high-resolution, 3D snapshots of DNA-based nanostructures containing various nanoparticles with nanometer precision. By comparing the observed positions of individual nanoparticles from their expected lattice positions, we can correlate the landscape of singular displacements to the collective motions of the lattice. This necessary connection allows us to construct the phonon spectrum and vibrational modes of our DNA-templated assemblies.

Our research aims to establish quantitative relationships between the design of DNA frames, assembled lattices and the resulting phonon properties of the assembled nanostructures. This knowledge has the potential to pave the way for the development of novel metamaterials with precisely controlled properties for applications in areas such as photonics, electronics, and energy storage.