skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Modern strategies in classical fields of nanoindentation: Semiconductors, ceramics, and thin films
Abstract Over the past three decades, nanoindentation has continuously evolved and transformed the field of materials mechanical testing. Once highlighted by the groundbreaking Oliver–Pharr method, the utility of nanoindentation has transcended far beyond modulus and hardness measurements. Today, with increasing challenges in developing advanced energy generation and electronics technologies, we face a growing demand for accelerated materials discovery and efficient assessment of mechanical properties that are coupled with modern machine learning-assisted approaches, most of which require robust experimental validation and verification. To this end, nanoindentation finds its unique strength, owing to its small-volume requirement, of fast-probing and providing a mechanistic understanding of various materials. As such, this technique meets the demand for rapid materials assessment, including semiconductors, ceramics, and thin films, which are integral to next-generation energy-efficient and high-power electronic devices. Here, we highlight modern nanoindentation strategies using novel experimental protocols outlined by the use of nanoindentation for characterizing functional structures, dislocation engineering, high-speed nanoindentation mapping, and accelerating materials discovery via thin-film libraries. We demonstrate that nanoindentation can be a powerful tool for probing the fundamental mechanisms of elasticity, plasticity, and fracture over a wide range of microstructures, offering versatile opportunities for the development and transition of functional materials. Graphical abstract  more » « less
Award ID(s):
2323936
PAR ID:
10595509
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Cambridge University Press (CUP)
Date Published:
Journal Name:
MRS Bulletin
Volume:
50
Issue:
6
ISSN:
0883-7694
Format(s):
Medium: X Size: p. 726-734
Size(s):
p. 726-734
Sponsoring Org:
National Science Foundation
More Like this
  1. Kirk S. Schanze, editor-in-chief (Ed.)
    Nanoindentation is an optimal technique for the measurement of thin film mechanical properties. Polymers present a unique problem in that their response to loading is time-dependent. Due to this, many of the most common nanoindentation methods are not suitable for probing polymer nanoscale properties. Despite this issue being well-known for decades, poly(3-hexylthiophene) has been exclusively analyzed by time-independent mechanical properties testing methods. Herein, we present a nanoindentation technique that analyzes the materials’ time-dependent response under both constant rate loading and step loading. By determining viscoelastic functions, we are able to extract the Young’s relaxation modulus of poly(3- hexylthiophene). The average Young’s modulus acquired from viscoelastic nanoindentation is determined to be 260 ± 27 MPa. These results are in excellent agreement with specialized mechanical tests for thin 
    more » « less
  2. Abstract In the last decade, organ-on-a-chip technology has been researched as an alternative to animal and cell culture models (Buhidma et al. in NPJ Parkinson’s Dis, 2020; Pearce et al. in Eur Cells Mater 13:1–10, 2007; Huh et al. in Nat Protoc 8:2135–2157, 2013). While extensive research has focused on the biological functions of these chips, there has been limited exploration of functional materials that can accurately replicate the biological environment. Our group concentrated on a lung-on-a-chip featuring a newly fabricated porous silicon bio-membrane. This bio-membrane mimics the interstitial space found between epithelial and endothelial cells in vivo, with a thickness of approximately 1 μm (Ingber in Cell 164:1105–1109, 2016). This study aims to establish a fabrication method for producing a thin, uniform porous silicon membrane with a predictablereduced modulus. We conducted mechanical and morphological characterization using scanning electron microscopy and nanoindentation. A small, parametric study was conducted to determine the reduced modulus of the porous silicon and how it may relate to the morphological features of the membrane. We compare our results to other works. Graphical Abstract 
    more » « less
  3. Abstract In the burgeoning field of spintronics, antiferromagnetic materials (AFMs) are attracting significant attention for their potential to enable ultra‐fast, energy‐efficient devices. Thin films of AFMs are particularly promising for practical applications due to their compatibility with spin‐orbit torque (SOT) mechanisms. However, studying these thin films presents challenges, primarily due to the weak signals they produce and the rapid dynamics driven by SOT, that are too fast for conventional electric transport or microwave techniques to capture. The time‐resolved magneto‐optical Kerr effect (TR‐MOKE) has been a successful tool for probing antiferromagnetic dynamics in bulk materials, thanks to its sub‐picosecond (sub‐ps) time resolution. Yet, its application to nanometer‐scale thin films has been limited by the difficulty of detecting weak signals in such small volumes. In this study, the first successful observation of antiferromagnetic dynamics are presented in nanometer‐thick orthoferrite films using the pump‐probe technique to detect TR‐MOKE signal. This paper report an exceptionally low damping constant of 1.5 × 10−4and confirms the AFM magnonic nature of these dynamics through angular‐dependent measurements. Furthermore, it is observed that electrical currents can potentially modulate these dynamics via SOT. The findings lay the groundwork for developing tunable, energy‐efficient spintronic devices, paving the way for advancements in next‐generation spintronic applications. 
    more » « less
  4. Abstract Dynamic molecular crystals are an emerging class of crystalline materials that can respond to mechanical stress by dissipating internal strain in a number of ways. Given the serendipitous nature of the discovery of such crystals, progress in the field requires advances in computational methods for the accurate and high–throughput computation of the nanomechanical properties of crystals on specific facets which are exposed to mechanical stress. Here, we develop and apply a new atomistic model for computing the surface elastic moduli of crystals on any set of facets of interest using dispersion–corrected density functional theory (DFT−D) methods. The model was benchmarked against a total of 24 reported nanoindentation measurements from a diverse set of molecular crystals and was found to be generally reliable. Using only the experimental crystal structure of the dietary supplement, L–aspartic acid, the model was subsequently applied under blind test conditions, to correctly predict the growth morphology, facet and nanomechanical properties of L–aspartic acid to within the accuracy of the measured elastic stiffness of the crystal, 24.53±0.56 GPa. This work paves the way for the computational design and experimental realization of other functional molecular crystals with tailor–made mechanical properties. 
    more » « less
  5. Abstract Nature has developed high‐performance materials and structures over millions of years of evolution and provides valuable sources of inspiration for the design of next‐generation structural materials, given the variety of excellent mechanical, hydrodynamic, optical, and electrical properties. Biomimicry, by learning from nature's concepts and design principles, is driving a paradigm shift in modern materials science and technology. However, the complicated structural architectures in nature far exceed the capability of traditional design and fabrication technologies, which hinders the progress of biomimetic study and its usage in engineering systems. Additive manufacturing (three‐dimensional (3D) printing) has created new opportunities for manipulating and mimicking the intrinsically multiscale, multimaterial, and multifunctional structures in nature. Here, an overview of recent developments in 3D printing of biomimetic reinforced mechanics, shape changing, and hydrodynamic structures, as well as optical and electrical devices is provided. The inspirations are from various creatures such as nacre, lobster claw, pine cone, flowers, octopus, butterfly wing, fly eye, etc., and various 3D‐printing technologies are discussed. Future opportunities for the development of biomimetic 3D‐printing technology to fabricate next‐generation functional materials and structures in mechanical, electrical, optical, and biomedical engineering are also outlined. 
    more » « less