Facile metal transfer method for fabricating unconventional metamaterial devices

Zhu, Mei; Lee, Chengkuo

doi:10.1364/ome.5.000733

Cited by 8 publications

(3 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The primary property of any flexible substrate is the ability to bend upon applying mechanical force. Some of the popular flexible substrates used for THz metamaterials include polyimide [17,31,69,73,[162][163][164][165][166], polydimethylsiloxane (PDMS) [167][168][169][170], polyethylene terephthalate (PET) [50,171], parylene [172], polyethylene naphthalate (PEN) [173,174], polypropylene [175], silicone [176] and silk [177][178][179][180]. In an initial work, metallic SRRs fabricated on PEN substrates were rolled into 3D tubes with varying diameter, as shown in figure 8(a) [173].…”

Section: Mechanical Reconfigurationmentioning

confidence: 99%

Terahertz MEMS metadevices

Pitchappa

Kumar

Singh

et al. 2021

J. Micromech. Microeng.

Self Cite

View full text Add to dashboard Cite

Terahertz (THz) part of the electromagnetic spectrum (0.1–10 THz) holds the key for next-generation high-speed wireless communication, non-destructive biosensing, fingerprint chemical detection and imaging for astronomy and security surveillance. The limited THz response of naturally occurring materials had left a technological gap in the THz region of the electromagnetic spectrum. Artificially engineered materials termed as ‘metamaterials’, have shown great potential in THz wave interaction and its active counterpart termed as ‘metadevices’ have been widely reported for on-demand manipulation of THz waves. One of the most efficient means of realizing metadevices is to reconfigure the shape of unit cells and hence the corresponding THz response. The 50+ years of development in microelectromechanical systems (MEMS) and the wide array of microactuator designs provide a perfect platform to achieve structural reconfiguration of microscale metamaterial unit cells in both in-plane and out-of-plane directions. In this review, we present a comprehensive overview of various MEMS approaches adopted for the demonstration of THz metadevices, their advantages and limitations. The future research directions of THz MEMS metadevices are also discussed. The seamless integration of matured MEMS technology with incipient THz metamaterials provides significant advantages in terms of enhanced performances, advanced functionalities and large scale manufacturability, that is critical for the development of future THz technologies.

show abstract

Section: Mechanical Reconfigurationmentioning

confidence: 99%

Terahertz MEMS metadevices

Pitchappa

Kumar

Singh

et al. 2021

J. Micromech. Microeng.

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, due to the weak adhesion forces between PDMS and metal, neither the deposition nor transfer of a metal electrode onto PDMS is easy. Therefore, a complicated process is required to enhance the adhesion between metal and PDMS using a chemical treatment or sacrificial layers [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. For example, Byun et al successfully transferred gold electrodes on PDMS by treating gold electrode with (3-mercaptopropyl)trimethoxysilane (MPTMS) for 20–540 min [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

Introduction of a Chemical-Free Metal PDMS Thermal Bonding for Fabrication of Flexible Electrode by Metal Transfer onto PDMS

et al. 2017

View full text Add to dashboard Cite

Polydimethylsiloxane (PDMS) is a flexible and biocompatible material widely used in the fabrication of microfluidic devices, and is often studied for the fabrication of flexible electrodes. The most popular method of fabricating a flexible electrode using PDMS is done by transferring a metal electrode onto said PDMS. However, the transfer process is difficult and the transferred metal layer is easily damaged due to inherently weak adhesion forces between the metal and PDMS, thus requiring a chemical treatment or sacrificial layer between the two. The fabrication process using a chemical treatment or sacrificial layer is complicated and expensive, which is the major limitation of using PDMS in the fabrication of flexible electrodes. This paper discusses the findings of a possible solution to create strong bonding between PDMS and various metals (copper, nickel and silver) using a chemical-free metal to PDMS thermal bonding technique. This method is the same as the PDMS curing process, but with a variation in the curing condition. The condition required to create strong bonding was studied by observing copper transferred by various PDMS curing conditions, including the standard condition. The condition creating the strong bonding was baking PDMS (5:1 = base polymer: curing agent) at 150 °C for 20 min. Experimentation showed that the optimum thickness of the transferred metal shows that the optimum thickness is approximately 500 nm, which allows for a higher resistance to stresses. The successful transfer of copper, nickel and silver layers onto PDMS with a stronger adhesion force opens up many new applications dealing with the fabrication of flexible electrodes, sensors, and flexible soft magnets.

show abstract

“…A stop band with bandwidth of as large as 1.40 THz was achieved. To improve the fabrication process, a facile metal transfer method was employed to create SRR patterns on PDMS surface, planar and otherwise, as well as PDMS-coated surfaces, such as paper, fabric and leaf [3]. Lastly, a design of 3D THz metamaterial device was proposed to be used in biomedical field for cancer cell studies, exploiting its structural similarities with the single-cell-capturing microfluidic devices.…”

Section: Introductionmentioning

confidence: 99%

The fascinating split-ring-resonators: progress in design, fabrication and applications of terahertz metamaterials

Zhu¹

2017

Proceedings of the Nano-Micro Conference 2017

Self Cite

View full text Add to dashboard Cite

Metamaterials with many unique optical properties are made of periodically arranged sub-wavelength metallic structures that are able to couple to external electromagnetic (EM) waves. One of such structures is the commonly used split-ring-resonators (SRR). In this talk, I will discuss and demonstrate some new progress we made on SRRbased terahertz metamaterials. By looking into the coupling between SRRs and the effect of incident polarization, we proposed a way to continuously modulate their resonances, changing the transmission intensity at resonant frequency from 20% to 80% [1]. We also designed a SRR-based polarization-insensitive broadband filter in THz range and discovered its effect in eliminating asymmetric characteristics in device structure [2]. A stop band with bandwidth of as large as 1.40 THz was achieved. To improve the fabrication process, a facile metal transfer method was employed to create SRR patterns on PDMS surface, planar and otherwise, as well as PDMS-coated surfaces, such as paper, fabric and leaf [3]. Lastly, a design of 3D THz metamaterial device was proposed to be used in biomedical field for cancer cell studies, exploiting its structural similarities with the single-cell-capturing microfluidic devices.

show abstract

Facile metal transfer method for fabricating unconventional metamaterial devices

Cited by 8 publications

References 37 publications

Terahertz MEMS metadevices

Terahertz MEMS metadevices

Introduction of a Chemical-Free Metal PDMS Thermal Bonding for Fabrication of Flexible Electrode by Metal Transfer onto PDMS

The fascinating split-ring-resonators: progress in design, fabrication and applications of terahertz metamaterials

Contact Info

Product

Resources

About