Powerful, Multifunctional Torsional Micromuscles Activated by Phase Transition

Liu, Kai; Cheng, Chun; Suh, Joonki; Tang‐Kong, Robert; Fu, Deyi; Lee, Sangwook; Zhou, Jian; Chua, Leon O.; Wu, Junqiao

doi:10.1002/adma.201304064

Cited by 82 publications

(83 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Fabrications : Poly‐crystalline VO 2 thin films and single‐crystal VO 2 microplates were prepared by pulsed laser deposition (PLD) and physical vapor deposition (PVD), respectively, on Si substrates with thermal SiO 2 (SiO 2 /Si). The details of syntheses were described in our previous work . Monolayer MoS 2 samples were synthesized by chemical‐vapor deposition (CVD) on SiO 2 /Si substrates using MoO 3 and S powders as precursors, which was also described in our previous work .…”

Section: Methodsmentioning

confidence: 99%

Modulating Photoluminescence of Monolayer Molybdenum Disulfide by Metal–Insulator Phase Transition in Active Substrates

Hou

Wang

et al. 2016

Small

Self Cite

View full text Add to dashboard Cite

The atomic thickness and flatness allow properties of 2D semiconductors to be modulated with influence from the substrate. Reversible modulation of these properties requires an "active," reconfigurable substrate, i.e., a substrate with switchable functionalities that interacts strongly with the 2D overlayer. In this work, the photoluminescence (PL) of monolayer molybdenum disulfide (MoS2 ) is modulated by interfacing it with a phase transition material, vanadium dioxide (VO2 ). The MoS2 PL intensity is enhanced by a factor of up to three when the underlying VO2 undergoes the thermally driven phase transition from the insulating to metallic phase. A nonvolatile, reversible way to rewrite the PL pattern is also demonstrated. The enhancement effect is attributed to constructive optical interference when the VO2 turns metallic. This modulation method requires no chemical or mechanical processes, potentially finding applications in new switches and sensors.

show abstract

Section: Methodsmentioning

confidence: 99%

Modulating Photoluminescence of Monolayer Molybdenum Disulfide by Metal–Insulator Phase Transition in Active Substrates

Hou

Wang

et al. 2016

Small

Self Cite

View full text Add to dashboard Cite

show abstract

“…A number of studies were focused on sizedependent transition in isolated nanoparticles and film grains due to importance of fundamental processes involved in the PT dynamics and prospective technological use of VO 2 -based materials. [9][10][11][12][13][14][15] The observations of spatially resolved PT in VO 2 at the nanoscale level were recently reported in several papers, which demonstrate noticeable size-dependent transition dynamics in nanoparticles and nanocrystalline films. [16][17][18][19][20][21] Despite significant effort in experimental and theoretical study of VO 2 , the problem related to the PT mechanism in this material is still far from complete understanding owing to variety of discrepant experimental data.…”

mentioning

confidence: 94%

Light scattering by epitaxial VO2 films near the metal-insulator transition point

Lysenko

Fernández

Rúa

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inImproved metal-insulator-transition characteristics of ultrathin VO2 epitaxial films by optimized surface preparation of rutile TiO2 substrates Appl. Phys. Lett.Comprehensive study of the metal-insulator transition in pulsed laser deposited epitaxial VO2 thin films Increased metal-insulator transition temperatures in epitaxial thin films of V 2 O 3 prepared in reduced oxygen environments Appl. Phys. Lett. 98, 152105 (2011); 10.1063/1.3574910 Metal-insulator transition in epitaxial V 1 − x W x O 2 ( 0 ≤ x ≤ 0.33 ) thin films Appl. Phys. Lett. 96, 022102 (2010);Experimental observation of metal-insulator transition in epitaxial films of vanadium dioxide is reported. Hemispherical angle-resolved light scattering technique is applied for statistical analysis of the phase transition processes on mesoscale. It is shown that the thermal hysteresis strongly depends on spatial frequency of surface irregularities. The transformation of scattering indicatrix depends on sample morphology and is principally different for the thin films with higher internal elastic strain and for the thicker films where this strain is suppressed by introduction of misfit dislocations. The evolution of scattering indicatrix, fractal dimension, surface power spectral density, and surface autocorrelation function demonstrates distinctive behavior which elucidates the influence of structural defects and strain on thermal hysteresis, twinning of microcrystallites, and domain formation during the phase transition. V C 2015 AIP Publishing LLC.

show abstract

“…Our study reveals the remarkable condensation of strain energy over perversions during their formation and the repulsive nature of the perversion-perversion interaction. These intrinsic properties of perversions may be exploited in the design of micromuscles (23) and soft robotics (24).…”

Section: Significancementioning

confidence: 99%

Emergent perversions in the buckling of heterogeneous elastic strips

Liu

Yao

Chiou

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A perversion in an otherwise uniform helical structure, such as a climbing plant tendril, refers to a kink that connects two helices with opposite chiralities. Such singularity structures are widely seen in natural and artificial mechanical systems, and they provide the fundamental mechanism of helical symmetry breaking. However, it is still not clear how perversions arise in various helical structures and which universal principles govern them. As such, a heterogeneous elastic bistrip system provides an excellent model to address these questions. Here, we investigate intrinsic perversion properties which are independent of strip shapes. This study reveals the rich physics of perversions in the 3D elastic system, including the condensation of strain energy over perversions during their formation, the repulsive nature of the perversion-perversion interaction, and the coalescence of perversions that finally leads to a linear defect structure. This study may have implications for understanding relevant biological motifs and for use of perversions as energy storers in the design of micromuscles and soft robotics.S pontaneous symmetry breaking provides a unifying conceptual understanding of emergent ordered structures arising in various condensed matters (1). In an elastic medium, which is one of the simplest organizations of matter, symmetry-breaking instabilities via buckling can lead to extraordinarily rich patterns and generate a wealth of shapes at multiple length scales that can be exploited in many scientific disciplines (2). A prototype of elastic buckling is the Euler instability of a homogeneous elastic rod under uniaxial compression at the ends that finally breaks the rotational symmetry (3). Introduction of extra structures in an elastic medium like mechanical heterogeneities (4), nonlinearity of materials (2), geometric asymmetry (5), or intrinsic curvature (6) provides new dimensions that can produce even richer buckling modes, including helices and perversions (6, 7), wavy structures (8), regular networks of ridges (9), and even selfsimilar fractal patterns (2, 10). Of these emergent symmetry broken structures, the helical shapes are of particular interest due to their ubiquitousness in nature and the strong connection with biological motifs, as noticed by Darwin in his 1875 book describing the curl of plant tendrils (11). Remarkably, biological helical structures permeate over several length scales from the developed helical valve on opening seed pods (12), to the regular chiral structures in the flagella of bacteria (13), the spiral ramps of rough endoplasmic reticulum (14), and the chromosome of Escherichia coli (15, 16).The proliferation of perversions in an otherwise uniform helical structure can further break the helical symmetry (Fig. 1A shows a typical perversion in the helix) (4, 6, 17). Here, a perversion refers to a kink that connects two helices with opposite chiralities. Therefore, perversions belong to a large class of fundamental defects in systems with discrete symmetry which have the n...

show abstract

Powerful, Multifunctional Torsional Micromuscles Activated by Phase Transition

Cited by 82 publications

References 29 publications

Modulating Photoluminescence of Monolayer Molybdenum Disulfide by Metal–Insulator Phase Transition in Active Substrates

Modulating Photoluminescence of Monolayer Molybdenum Disulfide by Metal–Insulator Phase Transition in Active Substrates

Light scattering by epitaxial VO2 films near the metal-insulator transition point

Emergent perversions in the buckling of heterogeneous elastic strips

Contact Info

Product

Resources

About