Abstract-Recent advances in the Metamaterial-inspired biosensors

Ahmed Salim, 

Sungjoon Lim

The most recent metamaterial-inspired biosensors have been reviewed by dividing GHz and THz domains.

https://www.sciencedirect.com/science/article/pii/S0956566318304639

Metamaterials (MM)-inspired microwave biosensors are a valuable addition to the field of diagnostic approaches and prognostic tools. The fundamental principle behind these biosensors is unique dielectric signatures corresponding to healthy/diseased tissues. Relying on nonionizing radiation and offering an increased resolution with accuracy comparable to that of ultrasound devices, they are an attractive solution for noninvasive and label-free biosensing applications. High-quality-factor MM-inspired resonators are integrated with microfluidics to accelerate the lab-on-chip and point-of-care diagnostic approaches owing to the small detection volume and overall compact size of these devices. A variety of biomolecular detection, glucose detection and hyperthermia treatment using state-of-the-art MM-inspired biosensors have been discussed. Optical transduction techniques (e.g., surface plasmon resonance) which enhance the sensitivity in terms of limit-of-detection and resolution, have also been outlined. Utilization of microwave biosensors as therapeutic agents is at its initial stages owing to lack of required sensitivity and reliability in recently proposed MM-inspired biosensors

Abstract-Angle- and Polarization-Insensitive Metamaterial Absorber using Via Array

Daecheon Lim

, Dongju Lee

 & Sungjoon Lim

http://www.nature.com/articles/srep39686

In this paper, we propose an angle- and polarization-insensitive metamaterial absorber. We design a metamaterial unit cell that is based on a split ring cross resonator (SRCR). We observe that the absorption frequency and absorption ratio are insensitive to incident angles when a via array surrounds the SRR. We demonstrate the effect of the via array using full-wave simulations by comparing the absorptivity of the SRCR with and without the via array. Because of the symmetric geometry, we also realize polarization insensitivity. We build the proposed absorber on a printed-circuit-board with 30 × 30 unit cells, and we demonstrate its performance experimentally in free space. Under normal incidence, the fabricated absorber shows 99.6% absorptivity at 11.3 GHz for all polarization angles, while for oblique incidence, the fabricated absorber maintains an absorptivity higher than 90% for incident angles up to 70° and 60° for transverse magnetic (TM) and transverse electric (TE) modes, respectively.

Abstract-Flexible inkjet-printed metamaterial absorber for coating a cylindrical object

Flexible inkjet-printed metamaterial absorber for coating a cylindrical object Hyung Ki Kim, Kenyu Ling, Kyeongseob Kim, and Sungjoon Lim  »View Author Affiliations

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-23-5-5898

Optics Express, Vol. 23, Issue 5, pp. 5898-5906 (2015)
http://dx.doi.org/10.1364/OE.23.005898

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In this paper, a novel flexible inkjet-printed metamaterial absorber is proposed. The unit cell of the metamaterial is designed with a modified Jerusalem-cross ring resonator and is inkjet printed with silver nanoparticle ink on a flexible polymer film. All fabrication processes are performed using a commercial printer (EPSON WF-7011). The absorber’s flexibility and absorption performance are demonstrated by measuring the absorption ratio after coating the proposed absorber on a cylindrical object with a radius of 4.56 cm. An absorption rate exceeding 99% is achieved at 9.21 GHz for both flat and cylindrical surfaces. In addition, the cylindrical model attains an absorption rate higher than 96% for all polarization angles, and a high absorption rate of 95% is preserved until the incident angle is less than 30þ.

© 2015 Optical Society of America

Abstract-Microfluidic tunable inkjet-printed metamaterial absorber on paper

Microfluidic tunable inkjet-printed metamaterial absorber on paper Kenyu Ling, Minyeong Yoo, Wenjing Su, Kyeongseob Kim, Benjamin Cook, Manos M. Tentzeris, and Sungjoon Lim  »View Author Affiliations

Optics Express, Vol. 23, Issue 1, pp. 110-120 (2015)
http://dx.doi.org/10.1364/OE.23.000110

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-23-1-110

In this paper, we propose a novel microfluidic tunable metamaterial (MM) absorber printed on a paper substrate in silver nanoparticle ink. The metamaterial is designed using a periodic array consisting of square patches. The conductive patterns are inkjet-printed on paper using silver nanoparticle inks. The microfluidic channels are laser-etched on polymethyl methacrylate (PMMA). The conductive patterns on paper and the microfluidic channels on PMMA are bonded by an SU-8 layer that is also inkjet-printed on the conductive patterns. The proposed MM absorber provides frequency-tuning capability for different fluids in the microfluidic channels. We performed full-wave simulations and measurements that confirmed that the resonant frequency decreased from 4.42 GHz to 3.97 GHz after the injection of distilled water into the microfluidic channels. For both empty and water-filled channels, the absorptivity is higher than 90% at horizontal and vertical polarizations.

© 2015 Optical Society of America