Abstract-Ti3C2Tx MXene Sponge Composite as Broadband Terahertz Absorber

Wenchao Shui, Jianmin Li,  Hao Wang, Yang Xing, Yilei Li, Qinghui Yang, Xu Xiao, Qiye Wen, Huaiwu Zhang

https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202001120

Terahertz (THz) absorption technology is promising in radar stealth, electromagnetic interference (EMI) shielding, and the upcoming 6G communication. However, the most popular metamaterial‐based THz absorbers suffer from complex fabrication process and/or narrowband characteristics. Here, a broadband, lightweight, and hydrophobic THz absorber is realized based on Ti3C2Tx MXene sponge foam (MSF) that is obtained by using a dip‐coating method. Due to the macroscopic impedance matching to free space and various microscopic morphologies of metallic Ti3C2Tx flakes inside porous architecture, the obtained MSF, with only 2 mm thickness, shows almost no THz reflection (minimum ≈ 0.00003%) and high THz absorption over 99.99% under the 100% qualified frequency bandwidth ranging from 0.3 to 1.65 THz. The new strategy of combining large‐pore‐size porous architecture with MXene‐like 2D metallic flakes paves a way to achieving high performance THz absorber with minimal thickness, which is of significance in electromagnetic stealth, shielding, and beyond.

Abstract-Three-dimensional metacrystals with a broadband isotropic diamagnetic response and an all-angle negative index of refraction

Su Xu, Jian-Bin Liu, Hao Wang, Ci-Kang Su, Hong-Bo Sun,

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-44-4-927&origin=search

Metamaterials (MMs) and photonic crystals (PhCs) exhibiting artificially engineered physical properties have been widely studied in the past decade. However, abnormal properties could only be proposed under a limited range of polarization and directions in most of the previous studies. It is still a challenge to realize an isotropic artificial material with multiple exotic electromagnetic properties. Here we report a three-dimensional metacrystal supporting full polarization and omni-directional incidence. The center-symmetric unit cell consists of non-resonant closed metallic loops on each surface of the dielectric cube. With the cross-scale dispersion engineering, the metacrystal can exhibit an isotropic diamagnetic response and an all-angle negative index of refraction simultaneously at the opposite sides of the MM-PhC transition region. An additional numerical analysis shows the good performance in terahertz and mid-infrared frequencies, which indicates its potential applications on multi-functional optical components with wide polarization-and-direction allowance.

© 2019 Optical Society of America

Abstract-Near-Infrared Laser-Driven in Situ Self-Assembly as a General Strategy for Deep Tumor Therapy

Fu-Hua Liu, Yong Cong, Guo-Bin Qi, Lei Ji, Zeng-Ying Qiao,  Hao Wang

https://pubs.acs.org/doi/10.1021/acs.nanolett.8b03174#

Nanotherapeutics have encountered some bottleneck problems in cancer therapy, such as poor penetration and inefficient accumulation in tumor site. We herein developed a novel strategy for deep tissue penetration in molecular level and near-infrared (NIR) laser guided in situ self-assembly to solve these challenges. For the proof-of-concept study, we synthesized the polymer–peptide conjugates (PPCs) composed of (i) poly(β-thioester) as thermoresponsive backbone, (ii) functional peptides (cytotoxic peptide and cell-penetrating peptide), and (iii) the NIR molecule with photothermal property. The PPCs in the molecular level with small size (<10 nm) can penetrate deeply into the interior of the tumor at body temperature. Under the irradiation of NIR laser, the temperature rise induced by photothermal molecules led to the intratumoral self-assembly of thermoresponsive PPCs. The resultant spherical nanoparticles can accumulate in tumor and enter cells effectively, inducing cell apoptosis by destroying mitochondria membrane. Through the site-specific size control, a variety of merits of PPCs are realized including deep tumor penetration, enhanced accumulation, and cellular internalization in vivo. Taking advantage of the NIR guided in situ assembly strategy, numerous polymeric or nanoscaled therapeutics with high anticancer activity can be exploited.

Abstract-Continuous-wave Y-band planar BWO with wide tunable bandwidth

Hongzhu Xi, Jianguo Wang, Zhaochang He, Gang Zhu, Yue Wang, Hao Wang, Zaigao Chen, Rong Li , Luwei Liu

https://www.nature.com/articles/s41598-017-18740-w

A high performance continuous-wave (CW) backward wave oscillator (BWO) with planar slow wave structure (SWS) and sheet electron beam in Y-band is presented in this paper. The mode selection is discussed by studying the dispersion curve of SWSs, distributions of the electric field, and particle-in-cell simulation results, showing that the designed BWO operates in the fundamental mode TM11. The planar SWSs are fabricated by using the UV-LIGA technology with the processing error less than 0.003 mm. The electron gun can provide the 2.5 mm × 0.14 mm sheet electron beam with maximum current density of 57 A/cm2 at the CW mode. Experimental results show that the developed BWO can operate in the fundamental mode TM11 and generate the state-of-art output power of 182 mW at the frequency of 0.3426 THz with a large frequency tuning range from 0.318 THz to 0.359 THz.