Hoang-Jyh Leu

Using patent analyses to monitor the technological trends in an emerging field of technology: a case of carbon nanotube field emission display

Carbon nanotube field emission display (CNT-FED) represents both emerging application of nanotechnology and revolutionary invention of display. Therefore, it is an important subject to monitor the states and trends of CNT-FED technology before the next stage of development. The present paper uses patent bibliometric analysis and patent network analysis to monitor the technological trends in the field of CNT-FED. These results firstly reveal the different aspects of patenting activities in the field of CNT-FED. Then, patent network analysis indicates the developing tendency of worldwide FED production based on the synthesis of CNT materials. Furthermore, key technologies of three clusters can be identified as the depositing CNT on substrate, coating phosphor on screen and assembling process for whole device. Finally, emitter material is taken for the key factor in R&D work to improve the efficacy in CNT-FED technology.

Biohydrogen production by dark fermentation: scaling-up and technologies integration for a sustainable system

Currently, the use of alternative renewable energies is broadly supported in many countries, some of which are seriously evaluating the possibility of using hydrogen as an alternative fuel in their power systems. Hydrogen production by biological processes, such as dark fermentation, is a very promising alternative. However, this process has only been studied on the laboratory scale, and there is limited experience at the pilot scale. The main reasons of non-scaling hydrogen production by dark fermentation at large scale are unpurified hydrogen production, stability of the bioprocesses, as well as their low conversion yields joined at the formation of byproducts. Improvement of energetic yields of dark fermentation requires a better knowledge of the microorganisms involved in the mixed culture and their possible interactions, as well as the use of appropriate substrates and strategies, such as solid-state fermentation, the purification of hydrogen and the coupling of dark fermentation with other biological processes as anaerobic digestion. The present work offers an overview of the current knowledge dealing with H2-production by dark fermentation and its integration into a concept of an environmental biorefinery. Several key points are addressed, such as the benefits of using local waste as substrates, the new solid-state fermentation processes, the coupling of hydrogen purification with the production process, the association of the H2-producing process with other biological processes, such as anaerobic digestion towards biohythane production (H2/CH4). Information about pilot plant experiments was added to illustrate the feasibility of producing fermentative hydrogen and methane from organic waste at a pilot scale, as developed at Feng Chia University (Taiwan).

Investigation of technological trends in flexible display fabrication through patent analysis

Abstract This paper uses patent network analysis to investigate technological trends in the field of flexible display fabrication through technology centrality index (TCI) and technology cycle time (TCT) index. The fabrication of electrophoretic display (EPD) was indicated as the key factor in future development of flexible display. Further, the critical technologies were obtained from cluster analysis, and the density index (DI) value of each cluster identified the invention of key materials for electro-optic display as the most important subject, especially in flexible EPD. Finally, recent journal publications and website reports using display key materials as electrophoretic ink could prove that development of EPD device was most important and close to marketing trend. The procedure of this patent network analysis presents significant insights quickly in the field of flexible display fabrication. This fruitful methodology is capable of supporting technological trends effectively for the researchers who are interested in scientific field.

A single Alq3 submicro-wire Schottky diode and its negative differential resistance

This study fabricated high-quality tris(8-hydroxyquinoline) aluminium (Alq3) submicro-wires as well as a Schottky diode with a single Alq3 submicro-wire across Ag electrodes. Rectifying and negative differential resistance (NDR) of the fabricated diode was obtained and the turn-on voltage and breakdown voltage was 4 V and 12 V, respectively. The NDR of the diode was observed when the forward bias exceeded 4 V and the peak-to-valley ratio in the current was more than 6 : 1 at room temperature. The mechanism of NDR in the Schottky diode was discussed. These results may facilitate applying Alq3 submicro-wires for advanced organic/inorganic hybrid nanostructure devices.

The living banana plant as a long-lasting battery cell

ABSTRACT Among citrus fruits, lemon is widely used as a low-power electrical source. Although, it can generate a potential difference, this phenomenon is only sustainable for few days, and no other alternative organism has been reported to provide a similar potential with longer duration. This study reports the discovery of living banana plant as an inexpensive, reliable, stable, and long-lasting power. A Zn anode and Cu cathode are inserted into banana plant to extract electricity, and the organic compounds of plant act as electrolyte. This new discovery may introduce an era of providing renewable energy to who live in proximity to banana plantations.

Carbon Nanotube Fabrication: Patent Analysis

Patent documents contain important results of research and development. These documents have long been recognized as a very rich and potentially fruitful source of data for the study of innovation and technological change (Choi et al., 2007). Patent analysis is a valuable method that transfers patent documents into systematic and useful information. The information is helpful to evaluate technological development, monitor technological trends, manage RD Bethune et al., 1993). The commonly manufacturing processes of CNTs contain different types of manufacturing technology such as arc-discharge, laser ablation, and chemical vapor deposition (CVD). Arc-discharge and laser ablation methods for the growth of CNTs have been actively pursued in the past ten years. Both methods involve the condensation of carbon atoms generated from evaporation of solid carbon sources. The temperatures involved in these methods are close to the melting temperature of graphite, 3000-4000oC. Recent interest in CVD nanotube growth is also due to the idea that aligned and ordered CNT structures can be grown on surfaces with control that is not possible with arc-discharge or laser ablation techniques.