Research

Overview

Despite breakthroughs in the scientific understanding of deformation processes, the mechanical properties of engineering materials remain limited to fractions of their theoretical values. One approach to unlocking improved material performance is through nanostructuring (i.e., controlling the organization of a material at the nanoscale). However, the preservation of nanostructured properties at macroscales remains a pervasive challenge. In the Advanced Materials and Microstructures Lab, we are interested in answering this overarching research question: how can materials be engineered at the nanoscale to translate into macroscale structures with unprecedented properties?. The breadth of this question touches on a diverse set of material systems including: 2D materials, nanostructured metals, and bioinspired materials.

2D Materials

GO-length scales

2D materials (i.e., materials that are one plane of atoms thick) are known to possess unprecedented physical properties. New structural motifs may therefore be envisioned, which leverage the extraordinary properties of 2D materials as building blocks in scalable lightweight structures. However, the realization of these materials systems inherently requires the interrogation of material properties and mechanics laws at the atomic scale, which presents a number of unique challenges for the materials science community. At the AMML we employ novel characterization protocols to reveal the length-scale dependent physical properties of these material systems. For examples of previous works by members of the lab on this topic, please see our publications page.

Key References:
*equal contribution

  1. X. Zhang*, H. Nguyen*, M. Daly, S. T. Nguyen, and H. D. Espinosa, Nanoscale 11 12305-12316, 2019.
  2. M. Daly*, C. Cao*, H. Sun, Y. Sun, T. Filleter, and C. V. Singh, ACS Nano 10 1939-1947, 2016.
  3. C. Cao*, M. Daly*, B. Chen, J. Y. Howe, C. V. Singh, T. Filleter, and Y. Sun, Nano Letters 15 6528-6534, 2015.
  4. C. Cao*, M. Daly*, C. V. Singh, Y. Sun and T. Filleter, Carbon 81 497-504, 2015.

Nanostructured Metals

Multilayer with nanocrystalline and coarse-grained components

Nanocrystalline metals are known to possess excellent strengths relative to traditional (i.e., coarse-grained) microstructures. However, this gain in strength is accompanied by a significant decrease in ductility due to transitions in deformation mechanisms from nanostructuring. One approach to overcome this limitation is to implement motifs with bimodal architectures, possessing both nanocrystalline and coarse-grained features. At the AMML we are investigating novel microstructure designs to circumvent traditional tradeoffs in strength and ductility – enabling enhanced material property offerings. For examples of previous works by members of the lab on this topic, please see our publications page.

 

Key References:

  1. M. Daly, A. Kumar, C. V. Singh, and G. D. Hibbard, International Journal of Plasticity, 130 102702, 2020.
  2. M. Daly, S. Haldar, V. K. Rajendran, J. McCrea, G. D. Hibbard, and C. V. Singh, Materials Science and Engineering: A, 771 138581, 2020.
  3. M. Daly, J. L. McCrea, B. A. Bouwhuis, C. V. Singh, and G. D. Hibbard, Materials Science and Engineering: A, 641 305-314, 2015.

Bioinspired Materials

Bioinspired helicoids

Through the process of evolution, nature has developed efficient microstructure design strategies that deliver high performance materials systems. One of the keys to the success of biological materials is the leveraging of nanostructured phases as constituents in structural materials. In this sense, nature has achieved an engineering feat that has eluded materials scientists. Namely, nature has developed voxel-level processes to fabricate complex microstructures that avoid the normal performance pitfalls encountered when scaling nanostructured materials. With the advent of additive manufacturing, voxel-level control of microstructure is now available to materials scientists – enabling synthetic replication of high performance biological systems.  At the AMML, we are interested in utilizing additive manufacturing technologies to design microstructures with unprecedented properties. For examples of previous works by members of the lab on this topic, please see our publications page.

Key References:

  1. A. Zaheri, J. Fenner, B. Russell, D. Restrepo, M. Daly, D. Wang, C. Hayashi, M. A. Meyers, P. D. Zavatierri, and H. D. Espinosa,
    Advanced Functional Materials, 1803073, 2018.
  2. M. J. Chon, M. Daly, B. Wang, X. Xiao, A. Zaheri, M. A. Meyers, and H. D. Espinosa, Journal of the Mechanical Behavior of Biomedical Materials, 76 30-37, 2017.

Shape Memory Alloys

Shape memory microgripper

Shape memory alloys (SMA)s are a class of materials that can undergo shape changes when heated above a characteristic transformation temperature. Traditional SMAs are limited to one transformation temperature, meaning that they can only “remember” one specific shape. At the AMML we are investigating techniques to overcome these limitations, leading to multifunctional smart devices that can remember several shapes. This unprecedented functionality enables finds applications in smart actuation systems in the automotive, aerospace, and biomedical industries. For examples of previous works by members of the lab on this topic, please see our publications page.

Key References:

  1. M. Daly, A. Pequegnat, Y. N. Zhou, and M. I. Khan, Journal of Intelligent Material Systems and Structures, 28 984-990, 2013.
  2. M. Daly, A. Pequegnat, Y. Zhou, and M. I. Khan, Smart Materials and Structures, 21 045018, 2012.