Tyler’s paper was published at Cell Reports Physical Science! Many Congratulations!

Aaron N. Michelson, Tyler J. Flanagan, Seok-Woo Lee*, Oleg Gang*, “Light-weight and high strength silica nanolattices templated from DNA origami,” Cell Reports Physical Science (2023) [PDF][web] – DOI:https://doi.org/10.1016/j.xcrp.2023.101475

Abstract: Continuous nanolattices are an emerging class of mechanical metamaterials that are highly attractive due to their superior strength-to-weight ratios, which originate from their spatial architectures and nanoscale-sized elements possessing near-theoretical strength. Rational design of frameworks remains challenging below 50 nm because of limited methods to arrange small elements into complex architectures. Here, we fabricate silica frameworks with ∼4- to 20-nm-thick elements using self-assembly and silica templating of DNA origami nanolattices and perform in situ micro-compression testing to examine the mechanical properties. We observe strong effects of lattice dimensions on yield strength and failure mode. Silica nanolattices are found to exhibit yield strengths higher than those of any known engineering materials with similar mass density. The robust coordination of the nanothin and strong silica elements leads to the combination of lightweight and high-strength framework materials offering an effective strategy for the fabrication of nanoarchitected materials with superior mechanical properties.

 

Shuyang’s nanoindentation study on SrNi2P2 and its Rhodium doped structure has been published at Journal of Materials Research! Congratulations! Two UConn undergraduate students (Kiera Burns and Aurora Buswell) participated in this research.

Shuyang Xiao, Sarshad Rommel, Kiera A. Burns, Aurora A. Buswell, Vladislav Borisov, Juan Schmidt, Roser Valentí, Paul C. Canfield, Mark Aindow, Seok-Woo Lee, “Effects of Rhodium doping on dislocation nucleation in a [001] SrNi2P2 single crystals under spherical nanoindentaiton,” Journal of Materials Research (2023) [PDF][web] – DOI: https://doi.org/10.1557/s43578-023-01073-y

Abstract: Nanoindentation was performed on SrNi₂P₂ single crystals and their dilute solid solutions, Sr(Ni_1−xRh_x)₂P₂ (x = 0 ~ 0.055), under [001] loading to investigate the effects of elemental doping on Young’s modulus and dislocation nucleation stress. The results show that Young’s modulus and the dislocation nucleation stress decrease as the Rh content increases, and their Rh content dependence also varies with the Rh content. Electron diffraction analysis and the anisotropic lattice distortion calculations revealed that a local structural transition from the orthorhombic superstructure to the tetragonal structure and local compressive residual stresses could be the main reasons for the decrease in Young’s modulus and dislocation nucleation stress, respectively. The overlap of stress–strain fields between Rh atoms and the associated local structural transition contribute to their Rh content dependence. The results also indicate that elemental doping does not necessarily strengthen materials if the incipient plasticity is controlled by dislocation nucleation, unlike conventional solid solution strengthening.

 

Farewell lunch with Shuyang and Jay. We wish both a great success in their next endeavor! Congratulations again on their graduation!

Tyler’s work at EAG Lab in Silicon Valley (CA) is highlighted at the MSE Department webpage! Excellent article!

EAG Laboratories Scientist Shares Insight into Nanotechnology Research

 

Many congratulations on Shuyang’s graduation. Shuyang received PhD degree, and his study focused on fundamental understanding of mechanical behavior of SrNi2P2 intermetallic compound. This material exhibits superplasticity via double lattice collapse and expansion process, and this discovery was published at Nano Letters. Shuyang also studied the temperature effect, the cyclic loading effect, and the solute effect on superplasticity. He also discovered the tension-compression asymmetry in superplasticity mechanism. Due to this asymmetry, SrNi2P2 exhibits relatively large temperature changes during cyclic loading and demonstrates a strong potential as an elastocaloric material!

Shuyang will come back to China and start to work on SiEn integrated circuit Co., Ltd. We hope he makes a great contribution to developing a future semiconductor technology. Many congratulations on all your outstanding achievements at UConn!!!

Congratulations on Jay’s graduation! Jay received M.S degree and made a significant contribution to fundamental understanding of mechanical behavior of wire-arc-additive-manufactured (WAAM) material. Jay discovered the high solute concentration at dendrite boundaries, and this periodic distribution of solutes lead to the Hall-Petch type behavior. This result is very important for the development of strong WAAM materials. Jay starts their next journey at Collins Aerospace! Good luck!