Microfluidic serpentine antennas with designed mechanical tunability

Huang, YongAn; Wang, Yezhou; Xiao, Lin; Liu, Huimin; Dong, Wen; Yin, Zhouping

doi:10.1039/c4lc00762j

Cited by 90 publications

(69 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, the ‘J-shaped’ stress-strain behavior can be controlled, through careful choices in geometry, to precisely match those of human skin, as supported by finite element analyses (FEA) and experiment. Specifically, filamentary networks adopt a hierarchical construction of lattice topologies 77-83 with horseshoe microstructures 46, 84-88 , as shown in Figure 1b 49 . These microscale features can be formed in a variety of materials (e.g, photodefinable polymers, metals and semiconductors) using lithographic approaches.…”

Section: Network Designmentioning

confidence: 99%

Design and application of ‘J-shaped’ stress–strain behavior in stretchable electronics: a review

et al. 2017

View full text Add to dashboard Cite

A variety of natural biological tissues (e.g., skin, ligaments, spider silk, blood vessel) exhibit ‘J-shaped’ stress-strain behavior, thereby combining soft, compliant mechanics and large levels of stretchability, with a natural ‘strain-limiting’ mechanism to prevent damage from excessive strain. Synthetic materials with similar stress-strain behaviors have potential utility in many promising applications, such as tissue engineering (to reproduce the nonlinear mechanical properties of real biological tissues) and biomedical devices (to enable natural, comfortable integration of stretchable electronics with biological tissues/organs). Recent advances in this field encompass developments of novel material/structure concepts, fabrication approaches, and unique device applications. This review highlights five representative strategies, including designs that involve open network, wavy and wrinkled morphoologies, helical layouts, kirigami and origami constructs, and textile formats. Discussions focus on the underlying ideas, the fabrication/assembly routes, and the microstructure-property relationships that are essential for optimization of the desired ‘J-shaped’ stress-strain responses. Demonstration applications provide examples of the use of these designs in deformable electronics and biomedical devices that offer soft, compliant mechanics but with inherent robustness against damage from excessive deformation. We conclude with some perspectives on challenges and opportunities for future research.

show abstract

Section: Network Designmentioning

confidence: 99%

Design and application of ‘J-shaped’ stress–strain behavior in stretchable electronics: a review

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Because of the considerable difference in the stiffness, the islands keep almost undeformed upon stretching, while the bridges unravel to accommodate the applied strain (Lacour et al, 2006; Lee et al, 2011). Therefore, a variety of design strategies have been proposed for the electrical interconnects, including the curvy configurations formed through postbuckling of straight ribbons (Sun et al, 2006; Ko et al, 2008; Xu et al, 2011), the planar filamentary configurations in the serpentine or fractal patterns (Gonzalez et al, 2009; Kim et al, 2009; Xu et al, 2013; Fan et al, 2014; Huang et al, 2014; Xu et al, 2014; Zhang et al, 2014; Zhu et al, 2014), and the planar configurations involving Kirigami patterns (Filipov et al, 2015; Song et al, 2015; Shyu et al, 2015; Zhang et al, 2015b). Of these design strategies, the serpentine interconnects have been widely exploited in various functional systems (Kim et al, 2008; Kim et al, 2011; Yang et al, 2015; Zhang et al, 2015a), because of the efficiency in the stretchability and relative simple geometry that facilitates the design and fabrication.…”

Section: Introductionmentioning

confidence: 99%

A finite deformation model of planar serpentine interconnects for stretchable electronics

Fan

Zhang

et al. 2016

International Journal of Solids and Structures

View full text Add to dashboard Cite

Lithographically defined interconnects with filamentary, serpentine configurations have been widely used in various forms of stretchable electronic devices, owing to the ultra-high stretchability that can be achieved and the relative simple geometry that facilitates the design and fabrication. Theoretical models of serpentine interconnects developed previously for predicting the performance of stretchability were mainly based on the theory of infinitesimal deformation. This assumption, however, does not hold for the interconnects that undergo large levels of deformations before the structural failure. Here, an analytic model of serpentine interconnects is developed starting from the finite deformation theory of planar, curved beams. Finite element analyses (FEA) of the serpentine interconnects with a wide range of geometric parameters were performed to validate the developed model. Comparisons of the predicted stretchability to the estimations of linear models provide quantitative insights into the effect of finite deformation. Both the theoretical and numerical results indicate that a considerable overestimation (e.g., > 50% relatively) of the stretchability can be induced by the linear model for many representative shapes of serpentine interconnects. Furthermore, a simplified analytic solution of the stretchability is obtained by using an approximate model to characterize the nonlinear effect. The developed models can be used to facilitate the designs of serpentine interconnects in future applications.

show abstract

“…This allowed the monitoring wrist flexion, vocal cord movements, and finger joints. Similarly in [75], a very interesting wearable serpentine microfluidic antenna was developed that mechanically tunes its resonant frequency as a function of applied strain in a predefined direction. The antenna, based on EGaIn fluid in Ecoflex substrate, underwent an almost linear drop in resonant frequency from 1.73 GHz to 1.25 GHz (with radiation efficiency >95%) only once the applied strain on the antenna moves from 0% to 50% in a particular direction.…”

Section: Wearable Lm Antennasmentioning

confidence: 99%

Liquid Metal Antennas: Materials, Fabrication and Applications

Paracha

Butt

Alghamdi

et al. 2019

Sensors

View full text Add to dashboard Cite

This work reviews design aspects of liquid metal antennas and their corresponding applications. In the age of modern wireless communication technologies, adaptability and versatility have become highly attractive features of any communication device. Compared to traditional conductors like copper, the flow property and lack of elasticity limit of conductive fluids, makes them an ideal alternative for applications demanding mechanically flexible antennas. These fluidic properties also allow innovative antenna fabrication techniques like 3D printing, injecting, or spraying the conductive fluid on rigid/flexible substrates. Such fluids can also be easily manipulated to implement reconfigurability in liquid antennas using methods like micro pumping or electrochemically controlled capillary action as compared to traditional approaches like high-frequency switching. In this work, we discuss attributes of widely used conductive fluids, their novel patterning/fabrication techniques, and their corresponding state-of-the-art applications.Most of the conventional antennas are fabricated by etching the copper cladding on the rigid substrates to form static conductor shapes. Such antennas are highly efficient but suffer from irreversible structure deformation and even damage when being bent or stretched beyond certain limits [3]. As alternatives, several types of copper-coated polymer substrates such as Kapton, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN) films have been investigated to accommodate the need in flexible applications such as antennas. Similar to conventional substrates, the electrical properties of these substrates also degrade after severe bending/stretching, which in turn reduces antenna efficiency. Another option is polymer-based materials such as polydimethylsiloxane (PDMS), which has been typically used in combination with copper foils to realize highly flexible antennas. However, the semi-rigid copper foils may potentially suffer from irreversible deformation after certain bending cycles. Alternatively, liquid metals can be injected into microfluidic channels to fabricate highly flexible and mechanically stable antennas without compromising their electrical properties [4].In [5], a broader review of fluidics-based tuning methods for the development of microwave components was presented. Although, this included a review of antennas based on dielectric/conductive fluids, it primarily covered flexible and frequency-tunable antenna/arrays and lacked depth on polarization/pattern reconfigurability techniques. Additionally, discussion of recent advancements in state-of-the-art liquid metal applications was also missing in [5]. In [6], a mini review of flexible and stretchable antennas based on textile materials was discussed. Here, the focus was on the benefits of conductive filler-based elastomers used in antennas for bio-integrated electronics applications and the trade-off between antenna stretchability and its performance. However, a detailed review of materials, novel fabrication te...

show abstract

Microfluidic serpentine antennas with designed mechanical tunability

Cited by 90 publications

References 24 publications

Design and application of ‘J-shaped’ stress–strain behavior in stretchable electronics: a review

Design and application of ‘J-shaped’ stress–strain behavior in stretchable electronics: a review

A finite deformation model of planar serpentine interconnects for stretchable electronics

Liquid Metal Antennas: Materials, Fabrication and Applications

Contact Info

Product

Resources

About