The MoSeS dynamic omnigami paradigm for smart shape and composition programmable 2D materials

AbstractThe properties of 2D materials can be broadly tuned through alloying and phase and strain engineering. Shape programmable materials offer tremendous functionality, but sub-micron objects are typically unachievable with conventional thin films. Here we propose a new approach, combining phase/strain engineering with shape programming, to form 3D objects by patterned alloying of 2D transition metal dichalcogenide (TMD) monolayers. Conjugately, monolayers can be compositionally patterned using non-flat substrates. For concreteness, we focus on the TMD alloy MoSe$${}_{2c}$$2cS$${}_{2(1-c)}$$2(1−c); i.e., MoSeS. These 2D materials down-scale shape/composition programming to nanoscale objects/patterns, provide control of both bending and stretching deformations, are reversibly actuatable with electric fields, and possess the extraordinary and diverse properties of TMDs. Utilizing a first principles-informed continuum model, we demonstrate how a variety of shapes/composition patterns can be programmed and reversibly modulated across length scales. The vast space of possible designs and scales enables novel material properties and thus new applications spanning flexible electronics/optics, catalysis, responsive coatings, and soft robotics.

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Strain Engineering in 2D Materials: Towards Strain Tunable Optoelectronic Devices

10.29363/nanoge.ngfm.2019.007 ◽

2019 ◽

Author(s):

Andres Castellanos-Gomez ◽

Patricia Gant ◽

Riccardo Frisenda

Keyword(s):

2D Materials ◽

Optoelectronic Devices ◽

Strain Engineering

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Integrating flexible electronics for pulsed electric field delivery in a vascularized 3D glioblastoma model

npj Flexible Electronics ◽

10.1038/s41528-021-00115-x ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Marie C. Lefevre ◽

Gerwin Dijk ◽

Attila Kaszas ◽

Martin Baca ◽

David Moreau ◽

...

Keyword(s):

Electric Field ◽

Electric Fields ◽

Flexible Electronics ◽

Soft Tissues ◽

Multiphoton Microscopy ◽

Membrane Integrity ◽

Tumor Model ◽

Pulsed Electric Fields ◽

In Ovo ◽

Cell Membrane Integrity

AbstractGlioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility of delivering pulsed electric fields with flexible electronics using an in ovo vascularized tumor model. We show with fluorescence widefield and multiphoton microscopy that pulsed electric fields induce vasoconstriction of blood vessels and evoke calcium signals in vascularized glioblastoma spheroids stably expressing a genetically encoded fluorescence reporter. Simulations of the electric field delivery are compared with the measured influence of electric field effects on cell membrane integrity in exposed tumor cells. Our results confirm the feasibility of flexible electronics as a means of delivering intense pulsed electric fields to tumors in an intravital 3D vascularized model of human glioblastoma.

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Second-harmonic generation enhancement in monolayer transition-metal dichalcogenides by using an epsilon-near-zero substrate

Nanoscale Advances ◽

10.1039/d0na00779j ◽

2021 ◽

Vol 3 (1) ◽

pp. 272-278

Author(s):

Pilar G. Vianna ◽

Aline dos S. Almeida ◽

Rodrigo M. Gerosa ◽

Dario A. Bahamon ◽

Christiano J. S. de Matos

Keyword(s):

Dielectric Constant ◽

Transition Metal ◽

Harmonic Generation ◽

Nonlinear Effect ◽

Second Harmonic ◽

2D Materials ◽

Transition Metal Dichalcogenides ◽

Transition Metal Dichalcogenide ◽

Metal Dichalcogenides ◽

Epsilon Near Zero

The scheme illustrates a monolayer transition-metal dichalcogenide on an epsilon-near-zero substrate. The substrate near-zero dielectric constant is used as the enhancement mechanism to maximize the SHG nonlinear effect on monolayer 2D materials.

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Reactive plasma cleaning and restoration of transition metal dichalcogenide monolayers

npj 2D Materials and Applications ◽

10.1038/s41699-020-00197-7 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Daniil Marinov ◽

Jean-François de Marneffe ◽

Quentin Smets ◽

Goutham Arutchelvan ◽

Kristof M. Bal ◽

...

Keyword(s):

High Temperature ◽

Transition Metal ◽

Field Effect Transistors ◽

Removal Rate ◽

2D Materials ◽

Scale Up ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Plasma Cleaning ◽

Transition Metal Dichalcogenide

AbstractThe cleaning of two-dimensional (2D) materials is an essential step in the fabrication of future devices, leveraging their unique physical, optical, and chemical properties. Part of these emerging 2D materials are transition metal dichalcogenides (TMDs). So far there is limited understanding of the cleaning of “monolayer” TMD materials. In this study, we report on the use of downstream H2 plasma to clean the surface of monolayer WS2 grown by MOCVD. We demonstrate that high-temperature processing is essential, allowing to maximize the removal rate of polymers and to mitigate damage caused to the WS2 in the form of sulfur vacancies. We show that low temperature in situ carbonyl sulfide (OCS) soak is an efficient way to resulfurize the material, besides high-temperature H2S annealing. The cleaning processes and mechanisms elucidated in this work are tested on back-gated field-effect transistors, confirming that transport properties of WS2 devices can be maintained by the combination of H2 plasma cleaning and OCS restoration. The low-damage plasma cleaning based on H2 and OCS is very reproducible, fast (completed in a few minutes) and uses a 300 mm industrial plasma etch system qualified for standard semiconductor pilot production. This process is, therefore, expected to enable the industrial scale-up of 2D-based devices, co-integrated with silicon technology.

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Comparing Donor- and Acceptor-Originated Exciton Dynamics in Non-Fullerene Acceptor Blend Polymeric Systems

Polymers ◽

10.3390/polym13111770 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1770

Author(s):

Chan Im ◽

Sang-Woong Kang ◽

Jeong-Yoon Choi ◽

Jongdeok An

Keyword(s):

Flexible Electronics ◽

Transient Absorption ◽

Film Formation ◽

Transient Absorption Spectroscopy ◽

Excitation Wavelength ◽

Polymeric Systems ◽

Donor And Acceptor ◽

Novel Material ◽

Spectrally Resolved ◽

Energy Strategies

Non-fullerene type acceptors (NFA) have gained attention owing to their spectral extension that enables efficient solar energy capturing. For instance, the solely NFA-mediated absorbing region contributes to the photovoltaic power conversion efficiency (PCE) as high as ~30%, in the case of the solar cells comprised of fluorinated materials, PBDB-T-2F and ITIC-4F. This implies that NFAs must be able to serve as electron donors, even though they are conventionally assigned as electron acceptors. Therefore, the pathways of NFA-originated excitons need to be explored by the spectrally resolved photovoltaic characters. Additionally, excitation wavelength dependent transient absorption spectroscopy (TAS) was performed to trace the nature of the NFA-originated excitons and polymeric donor-originated excitons separately. Unique origin-dependent decay behaviors of the blend system were found by successive comparing of those solutions and pristine films which showed a dramatic change upon film formation. With the obtained experimental results, including TAS, a possible model describing origin-dependent decay pathways was suggested in the framework of reaction kinetics. Finally, numerical simulations based on the suggested model were performed to verify the feasibility, achieving reasonable correlation with experimental observables. The results should provide deeper insights in to renewable energy strategies by using novel material classes that are compatible with flexible electronics.

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Strain Engineering of 2D Materials: Issues and Opportunities at the Interface

Advanced Materials ◽

10.1002/adma.201805417 ◽

2019 ◽

Vol 31 (45) ◽

pp. 1805417 ◽

Cited By ~ 94

Author(s):

Zhaohe Dai ◽

Luqi Liu ◽

Zhong Zhang

Keyword(s):

2D Materials ◽

Strain Engineering

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MoS2/h-BN/Graphene Heterostructure and Plasmonic Effect for Self-Powering Photodetector: A Review

Materials ◽

10.3390/ma14071672 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1672

Author(s):

Umahwathy Sundararaju ◽

Muhammad Aniq Shazni Mohammad Haniff ◽

Pin Jern Ker ◽

P. Susthitha Menon

Keyword(s):

Flexible Electronics ◽

Hexagonal Boron Nitride ◽

2D Materials ◽

Optical Power ◽

Active Regions ◽

Green Technology ◽

Plasmonic Effect ◽

Zero Bias ◽

Electrical Signals ◽

Self Powered

A photodetector converts optical signals to detectable electrical signals. Lately, self-powered photodetectors have been widely studied because of their advantages in device miniaturization and low power consumption, which make them preferable in various applications, especially those related to green technology and flexible electronics. Since self-powered photodetectors do not have an external power supply at zero bias, it is important to ensure that the built-in potential in the device produces a sufficiently thick depletion region that efficiently sweeps the carriers across the junction, resulting in detectable electrical signals even at very low-optical power signals. Therefore, two-dimensional (2D) materials are explored as an alternative to silicon-based active regions in the photodetector. In addition, plasmonic effects coupled with self-powered photodetectors will further enhance light absorption and scattering, which contribute to the improvement of the device’s photocurrent generation. Hence, this review focuses on the employment of 2D materials such as graphene and molybdenum disulfide (MoS2) with the insertion of hexagonal boron nitride (h-BN) and plasmonic nanoparticles. All these approaches have shown performance improvement of photodetectors for self-powering applications. A comprehensive analysis encompassing 2D material characterization, theoretical and numerical modelling, device physics, fabrication and characterization of photodetectors with graphene/MoS2 and graphene/h-BN/MoS2 heterostructures with plasmonic effect is presented with potential leads to new research opportunities.

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2D materials inks toward smart flexible electronics

Materials Today ◽

10.1016/j.mattod.2021.08.010 ◽

2021 ◽

Author(s):

Oyawale Adetunji Moses ◽

Libo Gao ◽

Haitao Zhao ◽

Zhuo Wang ◽

Mukhtar Lawan Adam ◽

...

Keyword(s):

Flexible Electronics ◽

2D Materials

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In-Plane Heterostructures Enable Internal Stress Assisted Strain Engineering in 2D Materials

Small ◽

10.1002/smll.201703512 ◽

2018 ◽

Vol 14 (15) ◽

pp. 1703512 ◽

Cited By ~ 2

Author(s):

Feng Liu ◽

Tzu-Chiang Wang ◽

Qiheng Tang

Keyword(s):

Internal Stress ◽

2D Materials ◽

Strain Engineering

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Climbing droplets driven by mechanowetting on transverse waves

Science Advances ◽

10.1126/sciadv.aaw0914 ◽

2019 ◽

Vol 5 (6) ◽

pp. eaaw0914 ◽

Cited By ~ 10

Author(s):

Edwin De Jong ◽

Ye Wang ◽

Jaap M. J. Den Toonder ◽

Patrick R. Onck

Keyword(s):

Electric Fields ◽

Digital Microfluidics ◽

Modern Technology ◽

Dynamic Surface ◽

Transverse Waves ◽

Flat Surfaces ◽

Inclined Surfaces ◽

Fluid Properties ◽

High Electric Fields ◽

New Applications

Many applications in modern technology, such as self-cleaning surfaces and digital microfluidics, require control over individual fluid droplets on flat surfaces. Existing techniques may suffer from side effects resulting from high electric fields and high temperatures. Here, we introduce a markedly different method, termed “mechanowetting,” that is based on the surface tension–controlled droplet motion on deforming surfaces. The method is demonstrated by transporting droplets using transverse surface waves on horizontal and (vertically) inclined surfaces at transport velocities equal to the wave speed. We fully capture the fundamental mechanism of the mechanowetting force numerically and theoretically and establish its dependence on the fluid properties, surface energy, and wave parameters. Mechanowetting has the potential to lead to a range of new applications that feature droplet control through dynamic surface deformations.

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