Bistable Physical Geometries for Terahertz Plasmonic Structures Using Shape Memory Alloys

Gupta, Barun; Pandey, Shashank; Zhang, Ting; Nahata, Ajay

doi:10.1002/adom.201601008

Cited by 17 publications

(11 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various tuning mechanisms have been studied and reported, such as electrical [46][47][48][49][50][51] , thermal [52][53][54][55] , optical [56][57][58][59][60][61][62][63] , magnetical [64][65][66][67][68] , mechanical stretching [69][70][71][72][73] , and micro-nanoelectromechanical systems (M-NEMS) [74][75][76][77][78][79][80][81][82][83][84] . M-NEMS, which uses a combination of electrical, mechanical, and/or thermal control mechanisms to add tunability to current passive devices, is a well-known technology for designing reconfigurable devices in a variety of applications.…”

Section: Introductionmentioning

confidence: 99%

Tunable and reconfigurable metasurfaces and metadevices

Nemati

Wang

Hong

et al. 2018

Opto-Electronic Advances

328

205

View full text Add to dashboard Cite

Metasurfaces, two-dimensional equivalents of metamaterials, are engineered surfaces consisting of deep subwavelength features that have full control of the electromagnetic waves. Metasurfaces are not only being applied to the current devices throughout the electromagnetic spectrum from microwave to optics but also inspiring many new thrilling applications such as programmable on-demand optics and photonics in future. In order to overcome the limits imposed by passive metasurfaces, extensive researches have been put on utilizing different materials and mechanisms to design active metasurfaces. In this paper, we review the recent progress in tunable and reconfigurable metasurfaces and metadevices through the different active materials deployed together with the different control mechanisms including electrical, thermal, optical, mechanical, and magnetic, and provide the perspective for their future development for applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Tunable and reconfigurable metasurfaces and metadevices

Nemati

Wang

Hong

et al. 2018

Opto-Electronic Advances

328

205

View full text Add to dashboard Cite

show abstract

“…Shape memory alloys exhibit hysteresis as they undergo a reversible thermally induced phase transition. In the case of Nitinol foils, we measured the hysteresis properties of the alloy by directly measuring the metal temperature as it thermally cycled . In the case of the Flexinol wires, we were not able to measure the wire temperatures directly, since a portion of these wires was embedded within PDMS.…”

mentioning

confidence: 99%

An Electrically Tunable Terahertz Plasmonic Device Based on Shape Memory Alloys and Liquid Metals

Zhou

Zhang

Guruswamy

et al. 2018

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

plasmonic structures are particularly interesting because conventional metals exhibit extremely low loss over the length scales relevant to most devices. [7] This results from the high conductivity of most metals, but also limits their applicability to passive devices, since their conductivities cannot be easily altered. While such devices are extremely useful, it is also highly desirable to create structures that are active, such that the THz response can be modulated or continuously tuned.In the long wavelength regime, which includes the THz spectral band that ranges from 100 GHz to 10 THz, [8] a broad range of exotic metals have been shown to support relatively low loss propagation of SPPs. Such materials are attractive because they allow for dynamic changes in the optical response. These include semiconductors, [9,10] graphene, [11,12] superconductors, [13,14] and phase-change materials such as VO 2 , [15] which can have their dielectric properties altered via optical, electrical, or thermal excitation. Analogous capabilities have also been shown with metamaterials. [16,17] Such changes generally modify the conductivity of the material and, thus, only modulate the amplitude of the response function.Tuning of the spectral response, on the other hand, requires either a change in the physical dimensions of the structure or a change in the refractive index of the surrounding dielectric medium. Both approaches have been used with metamaterial devices, where changes have been made to the unit cell properties. [18][19][20][21][22] Even then, recent examples of frequency tuning have been limited to ≈5%. [22] In the case of plasmonic structures, where the response is associated with the propagation properties of SPPs over larger length scales, there are few demonstrations of frequency tuning. [23] In this submission, we describe a THz plasmonic device in which the transmission resonances can be continuously tuned electrically by changing the length of the metallic structure. The device is based on a periodic array of subwavelength apertures that combines the advantageous attributes of both liquid metals and shape memory alloys. The former material can be stretched and otherwise deformed without buckling or creating cracks or voids that penetrate the entire metal layer, while the latter material can change shape and be returned to its original form by simply changing the temperature. The specific device we have created is defined by injecting a liquid metal (eutectic gallium An electrically tunable terahertz (THz) plasmonic device is designed and fabricated using liquid metals (eutectic gallium indium) and shape memory alloy wires (Flexinol). The liquid metal is injected into the voids of a poly(dimethyl) siloxane microfluidic mold forming a periodic array of subwavelength apertures, while the wires are inserted into the elastomer below the metal plane. When a DC voltage is applied to the wires, they contract via Joule heating, reducing the aperture periodicity and blueshifting the transmission resonances of the device...

show abstract

“…Active devices include a varactor diode, triode, sensor, and so on. At present, the regulation methods of the tunable metasurface mainly include mechanical control [ 71 , 72 , 73 ], electric control [ 74 , 75 ], temperature control [ 76 ], and light control [ 77 ]. Mechanical control is to manipulate the phase by adjusting the physical size or rotation angle.…”

Section: Introductionmentioning

confidence: 99%

Evolution of the Electromagnetic Manipulation: From Tunable to Programmable and Intelligent Metasurfaces

Luo

Hao

et al. 2021

Micromachines

View full text Add to dashboard Cite

Looking back on the development of metamaterials in the past 20 years, metamaterials have gradually developed from three-dimensional complex electromagnetic structures to a two-dimensional metasurface with a low profile, during which a series of subversive achievements have been produced. The form of electromagnetic manipulation of the metasurface has evolved from passive to active tunable, programmable, and other dynamic and real-time controllable forms. In particular, the proposal of coding and programmable metasurfaces endows metasurfaces with new vitality. By describing metamaterials through binary code, the digital world and the physical world are connected, and the research of metasurfaces also steps into a new era of digitalization. However, the function switch of traditional programmable metamaterials cannot be achieved without human instruction and control. In order to achieve richer and more flexible function regulation and even higher level metasurface design, the intelligence of metamaterials is an important direction in its future development. In this paper, we review the development of tunable, programmable, and intelligent metasurfaces over the past 5 years, focusing on basic concepts, working principles, design methods, manufacturing, and experimental validation. Firstly, several manipulation modes of tunable metasurfaces are discussed; in particular, the metasurfaces based on temperature control, mechanical control, and electrical control are described in detail. It is demonstrated that the amplitude and phase responses can be flexibly manipulated by the tunable metasurfaces. Then, the concept, working principle, and design method of digital coding metasurfaces are briefly introduced. At the same time, we introduce the active programmable metasurfaces from the following aspects, such as structure, coding method, and three-dimensional far-field results, to show the excellent electromagnetic manipulation ability of programmable metasurfaces. Finally, the basic concepts and research status of intelligent metasurfaces are discussed in detail. Different from the previous programmable metamaterials, which must be controlled by human intervention, the new intelligent metamaterials control system will realize autonomous perception, autonomous decision-making, and even adaptive functional manipulation to a certain extent.

show abstract

Bistable Physical Geometries for Terahertz Plasmonic Structures Using Shape Memory Alloys

Cited by 17 publications

References 34 publications

Tunable and reconfigurable metasurfaces and metadevices

Tunable and reconfigurable metasurfaces and metadevices

An Electrically Tunable Terahertz Plasmonic Device Based on Shape Memory Alloys and Liquid Metals

Evolution of the Electromagnetic Manipulation: From Tunable to Programmable and Intelligent Metasurfaces

Contact Info

Product

Resources

About