Controlling Macroscale Morphology in DNA-Based Assembly Using Acoustic Energy

One of the main challenges of developing bottom-up designed materials is the issue of scaling their formation and shaping them into a desired morphology. A high degree of nanoscale control hinders the ability to form nanomaterials with predefined macroscale morphology. DNA nanotechnology allows accurate spatial control at the nanoscale which enables fabrication of intricate organizations; yet, structural arrangement at the macroscale remains a challenge. We developed an assembly approach driven by acoustic waves in order to control the morphology of DNA-assembled materials at the scales from tens of microns to millimeters, thus complementing a nanoscale assembly regime offered by DNA-guided methods. Specifically, we explored the use of standing surface acoustic waves (SSAW) to direct assembly and control morphology of DNA origami based crystal lattices. By controlling both acoustic forces and temperature, we investigated the assembly process at different scales by a combination of optical microscopy, small-angle x-ray scattering and electron microscopy techniques. We further studied the nucleation, crystal fusion and growth under different acoustic conditions. The developed approach allows to form macroscale nanomaterials with prescribed morphology, as defined by the acoustic field, while their nanoscale organization is programmed by DNA. Our experimental observations are supported by a model that incorporates nucleation dynamics, diffusion-limited growth, and the effects of acoustic driving. The model provided valuable insights into the impact of acoustic waves on suppressed nucleation and crystal growth. Overall, our study demonstrates the potential of acoustic waves as a complementary method for controlling the morphology of DNA-assembled nanomaterials at the macroscale. This approach expands the scope of DNA nanotechnology and paves the way for the fabrication of nanomaterials with tailored properties and functionalities for a wide range of applications.