Smart Processing for Ceramics Structure Tectonics: Fabrication of Dielectric Micro Patterns for Artificial Photosynthesis in Terahertz Wave Regions by Using Stereolithography

2010 ◽  
Vol 63 ◽  
pp. 141-146
Author(s):  
Soshu Kirihara ◽  
Naoki Komori ◽  
Noritoshi Ohta

Smart processing for ceramics structure tectonics is new strategy of science and engineering to create novel functional materials with special patterns and morphologies. In this lecture, various investigations to develop the functionally structured materials by using smart processes of stereo- lithography will be introduced. For example, photonic crystals with periodic arrangements in dielectric constants are strong candidates of artificial functional materials to control electromagnetic wave energies effectively. Special modifications of dielectric micro patterns to harmonize electromagnetic waves in terahertz frequency ranges with molecule vibrations of various biochemical solutions will be introduced as investigative results of artificial photosynthesis.

2021 ◽  
Vol 22 (9) ◽  
pp. 4543
Author(s):  
Xuan-Hung Pham ◽  
Seung-min Park ◽  
Bong-Hyun Jun

Nano/micro particles are considered to be the most valuable and important functional materials in the field of materials science and engineering [...]


2018 ◽  
Vol 64 ◽  
pp. 131-148
Author(s):  
J. Brian Davies

Alex Cullen combined the sharpest of scientific minds with a gentle personality and a great sense of humour. He was Professor and Head of the Department of Electrical Engineering at Sheffield from 1955 to 1967, and then Head of the Department of Electrical Engineering at University College London (UCL) until 1980. He continued his research there as a Science and Engineering Research Council Senior Fellow until 1985, and for some years as Research Fellow of UCL. His research concerned electromagnetic waves over a wide range of microwave devices and measurement techniques, the latter at a fundamental level. These contributions were of a highly innovative and ‘ground-breaking’ nature. He was appointed OBE in 1960, and elected Fellow of the Royal Society in 1977. He was an accomplished jazz musician, playing drums and clarinet. He was a signatory of a letter to The Times in January 1986, calling on Prime Minister Margaret Thatcher to ‘Save British Science’. This led to the foundation of the Save British Science pressure group, now the Campaign for Science and Engineering (CaSE), which has built up an enviable reputation with politicians and the media in representing the concerns of scientists and engineers. When (now Sir) Eric Ash left UCL in 1985 to become Rector of Imperial College, he remarked that Alex was ‘the last gentleman in the business’.


2020 ◽  
Vol 31 (28) ◽  
pp. 282001
Author(s):  
Han Zhou ◽  
Chengyu Xiao ◽  
Zhiwei Yang ◽  
Yijia Du

2013 ◽  
Vol 427-429 ◽  
pp. 2864-2869
Author(s):  
Zhi Ren ◽  
Ya Nan Cao ◽  
Shuang Peng ◽  
Hong Jiang Lei

The terahertz wave is a kind of electromagnetic waves which locates between millimeter waves and infrared lightwaves, and the frequency range is 0.14THz~10THz. Terahertz is used as a carrier wave to communicate with each other because it has large bandwidth which can support Gbps wireless data rates. Therefore, terahertz communication technologies become research hot spots in recent years. However, its still rare in MAC protocol of terahertz ultra-high data-rate wireless networks at present. In order to realize wireless access of ultra-high data-rate under the condition of terahertz carrier frequency, a novel MAC protocol is proposed in this paper. The improved MAC protocol which makes the maximum data rates reach up to 10Gbps or higher is designed by new MAC control mechanisms, new time-slots allocation schemes and new superframe structure. Theoretical analysis and simulation results show that the new proposed MAC protocol of terahertz ultra-high data-rate wireless networks can operation normally, and the maximum data rate can reach up to 19.2Gbps. This maximum data rate is 2 times higher than 5.78 Gbps which IEEE 802.15.3c can achieve.


2006 ◽  
Vol 45 ◽  
pp. 1139-1144
Author(s):  
Soshu Kirihara ◽  
Yoshinari Miyamoto

Three-dimensional electromagnetic or photonic crystals with periodic variations of the dielectric constants were fabricated by using a rapid prototyping method called stereolithography. Millimeter-order epoxy lattices with a diamond structure were designed to reflect electromagnetic waves by forming an electromagnetic band gap in GHz range. Titania based ceramic particles were dispersed into the lattice to control the dielectric constant. The diamond lattice structures formed the perfect band gap reflecting electromagnetic waves for all directions. The location of the band gap agreed with the band calculation using the plane wave propagation method. The diamond structures with graded lattice spacing were successfully fabricated as well, resulting in the directional transmission of microwaves. The stretching ratio of the lattice spacing in the crystal structure was changed according to the electromagnetic band calculation. A microwave antenna head composed of the diamond structure with graded lattice spacing was fabricated which achieved the unidirectional transmission.


2018 ◽  
Vol 51 (46) ◽  
pp. 464002 ◽  
Author(s):  
A V Sidorov ◽  
S V Golubev ◽  
S V Razin ◽  
A P Veselov ◽  
A V Vodopyanov ◽  
...  

Photonics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Kazutoshi Kato

Beam forming and beam steering are inevitable technologies for the practical application of high-frequency electromagnetic waves. Specifically, beam control technology using a phased array for terahertz waves above 100 GHz is necessary to realize the future of high-speed wireless communication. By photomixing, which is a promising method for generating terahertz waves, the phase of the generated waves can be tuned in the optical domain, so that the beam from the phased array can be controlled by photonics technologies. Directing the beam of a terahertz wave enables wireless communication to be improved not only via an increase in power efficiency but also in security in the physical layer of the wireless transmission. By utilizing this advantage and using coherent detection at the receiver, a secured wireless communication system is proposed, and the fundamental mechanism is demonstrated in a feasibility experiment.


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