• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.10
• /
• pp.438-442
• /
• 2005

Si nanocrystal (Si NC) memory device has several advantages such as better retention, lower operating voltage, reduced punch-through and consequently a smaller cell area, suppressed leakage current. However, the physical and electrical reasons for this behavior are not completely understood but could be related to interface states of Si NCs. In order to find out this effect, we characterized electrical properties of Si NCs embedded in a SiO$_{2}$ layer by scanning probe microscopy (SPM). The Si NCs were generated by the laser ablation method with compressed Si powder and followed by a sharpening oxidation. In this step Si NCs are capped with a thin oxide layer with the thickness of 1$\~$2 nm for isolation and the size control. The size of 51 NCs is in the range of 10$\~$50 m and the density around 10$^{11}$/cm$^{2}$ It also affects the interface states of Si NCs, resulting in the change of electrical properties. Using a conducting tip, the charge was injected directly into each Si NC, and the image contrast change and dC/dV curve shift due to the trapped charges were monitored. The results were compared with C-V characteristics of the conventional MOS capacitor structure.

• Tribology and Lubricants
• /
• v.16 no.5
• /
• pp.389-394
• /
• 2000

Scanning Probe Microscope (SPM) such as Scanning Tunneling Microscope (STM) and Atomic Force Microscope (AEM) was shown to be the powerful tool for nano-scale characterization of material surfaces. Using this technique, surface morphology of the cyclically deformed Cu or Cu-Al single crystal was observed. The surface became proportionately rough as the number of cycles increased, but after some number of cycles no further change was observed. Slip steps with the heights of 100 to 200 nm and the widths of 1000 to 2000 nm were prevailing at the stage. The slipped distance of one slip system at the surface was not uniform, and formation of the extrusions or intrusions was assumed to occur such place. By comparing the morphological change caused by crystallographic orientation, strain amplitude, number of cycles or stacking fault energy, some interesting results which help to clarify the basic mechanism of fatigue damage were obtained. Furthermore, applicability of the scanning tunneling microscopy to fatigue damage is discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1228-1231
• /
• 2005

This paper reports about the development of scanning probe microscopy (SPM) tip with multi-walled carbon nanotube (MWNT). For making a carbon nanotube (CNT) modified tips, AC electric field which causes the dielectrophoresis was used for alignment and deposition of CNTs to the metal coated SPM tip. By dropping the MWNT solution and applying an electric field between an SPM tip and an electrode, MWNTs which were dispersed into a diluted solution were directly assembled onto the apex of the SPM tips due to the attraction by the dielectrophoretic force. In this paper, we investigate experimental conditions about the alignment of the CNT to tip axis according to the change of the angle between a tip and an electrode. Experimental results are presented, and then fabricated CNT tips are showed and measurement results for 15nm gold particles are compared with that of the conventional silicon tip.

• Transactions of the Society of Information Storage Systems
• /
• v.1 no.1
• /
• pp.73-77
• /
• 2005

In this paper, a new silicon nitride cantilever integrated with silicon heater and piezoelectric sensor has been firstly developed to improve the uniformity of the initial bending and the mechanical stability of the cantilever array for thermo-piezoelectric SPM(scanning probe microscopy) -based data storages. This nitride cantilever shows thickness uniformity less than $2\%$. Data bits of 40 nm in diameter were recorded on PMMA film. The sensitivity of the piezoelectric sensor was 0.615 fC/nm after poling the PZT layer. For high speed operation, 128${\times}$128 probe array was developed.

• The Korean Journal of Food & Health Convergence
• /
• v.10 no.3
• /
• pp.19-22
• /
• 2024

The field of synthetic biology has emerged in response to the ongoing progress in the life sciences. Advances have been made in medicine, farming, eating, making materials, and more. Synthetic biology is the exploration of using living organisms to create new organisms. By manipulating specific genes to express targeted proteins, proteins can be created that are both productive and cost-effective. Solid-phase extraction (SPE) and liquid-liquid extraction (LLE) are employed for protein separation during the production process involving microorganisms. This study centers on Scanning Probe Microscopy (SPM) to showcase its utility in the food industry and food management. SPE is predominantly utilized as a pretreatment method to eliminate impurities from samples. In comparison to LLE, this method presents benefits such as decreased time and labor requirements, streamlined solvent extraction, automation capabilities, and compatibility with various other analytical instruments. Anion exchange chromatography (AEC) utilizes a similar methodology. Pharmaceutical companies utilize these technologies to improve the purity of biopharmaceuticals, thereby guaranteeing their quality. Used in the food and beverage industry to test chemical properties of raw materials and finished products. This exemplifies the potential of these technologies to enhance industrial development and broaden the scope of applications in synthetic biology.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1999.06a
• /
• pp.67-72
• /
• 1999

Scanning probe Microscope(SPM) such as Scanning Tunneling Microscope(STM) and Atomic Force Microscope(AFM) was shown to be the powerful tool for nano-scale characterization of material surfaces Using this technique, surface morphology of the cyclically deformed Cu or Cu-Al single crystal was observed. The surface became proportionately rough as the number of cycles increased, but after some number of cycles no further change was observed. Slip steps with the heights of 100 to 200 nm and the widths of 1000 to 2000 nm were prevailing at the stage. The slipped distance of one slip system at the surface was not uniform. and formation of the extrusions or intrusions was assumed to occur such place. By comparing the morphological change caused by crystallographic orientation, strain amplitude, number of cycles or stacking fault energy, some interesting results which help to clarify the basic mechanism of fatigue damage were obtained. Furthermore, applicability of the scanning tunneling microscopy to fatigue damage is discussed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.4-4
• /
• 2010

박막의 물성을 분석하는 방법에는 광학을 이용한 분광학 분석법과 나노크기의 tip을 이용한 나노트라이볼로지 분석법이 대표적이라 할 수 있다. 분광학 분석법에는 주로 X-ray 회절분석, Raman 분광기, IR 분광기 등등이 가장 대표적으로 사용되어지는 분석 장치들이다. 이러한 분광학 분석은 광학을 시료에 조사하여 이로부터 획득되는 강도(intensity)를 분석하는 방법으로 간접적인 분석이라 할 수 있다. 이에 반하여 나노트라이볼로지는 나노크기의 tip을 이용하여 시료 표면을 직접적인 방법으로 분석하여 시료의 형상, 탄성, 강도, 마찰력 등의 정보를 제공하며, tip에의 전기적 신호를 부과하여 시료 표면의 국부적인 potential, electric current를 측정하게 된다. 이에 해당되는 대표적인 분석 장치로는 nano-indenter system과 SPM (Scanning Probe Microscopy)이 있다. 따라서, 이 논문에서는 나노트라이볼로지의 대표적인 장치인 nano-indenter system과 SPM에 대한 간단한 원리를 소개하고 다양한 분야에 대한 실제적인 분석을 사례를 통하여 나노트라이볼로지의 가치를 확인하고자 한다.

• Advances in nano research
• /
• v.1 no.3
• /
• pp.133-151
• /
• 2013

The availability of advanced nanotechnological methodologies (experimental and theoretical) has widened the investigation of biological/organic matter in interaction with substrates. Minerals are good candidates as substrates because they may present a wide variety of physico-chemical properties and surface nanostructures that can be used to actively condense and manipulate the biomolecules. Scanning Probe Microscopy (SPM) is one of the best suited techniques used to investigate at a single molecule level the surface interactions. In addition, the recent availability of high performance computing has increased the possibility to study quantum mechanically the interaction phenomena extending the number of atoms involved in the simulation. In the present paper, firstly we will briefly introduce new SPM technological developments and applications to investigate mineral surfaces and mineral-biomolecule interaction, then we will present results on the specific RNA-mineral interaction and recent basics and applicative achievements in the field of the interactions between other fundamental biological molecules and mineral surfaces from both an experimental and theoretical point of view.

• Polymer Science and Technology
• /
• v.15 no.3
• /
• pp.363-373
• /
• 2004

1980년대 초, IBM의 과학자들에 의해 양자역학 현상에 기초한 새로운 현미경이 발명되었다. 뾰족한 금속 팁에 전압을 걸고 전도성 시료의 표면에 접근시키면, 팁이 표면에 접촉하기 직전에 터널링에 의한 전류가 흐르게 된다. 이 전류는 거리에 매우 민감해서 고체 표면에 배열된 원자들에 의해 형성되는 표면 굴곡 (surface corrugation)이 분간 가능하였다. 이 기계가 바로 STM (Scanning Tunneling Microscope)이다 (그럼 1). 이 발명이 있기까지의 약 2세기 가량의 시간 동안 "누구에 의해서도 결코 감지된 적 없는" (H. J. Robinson, Physics Today, March, 24, 1984.) 원자와 분자는 과학자들의 논리 속에 이론상으로 존재할 뿐이었다. STM의 발명으로 인해 인류는 바야흐로 개개의 원자와 분자를 직접적으로 감지할 수 있게 되었던 것이다. 처음으로 STM을 이용하여 원자해상도로 본 표면은 실리콘의 안정한 표면인 Si (111)-7${\times}$7 표면이었는데, 이러한 실리콘 표면의 STM 사진의 예를 그림 2에 나타내었다. (중략)타내었다. (중략)

• Journal of the Korean Ceramic Society
• /
• v.54 no.4
• /
• pp.261-271
• /
• 2017

Environment-friendly $(K,Na)NbO_3-based$ (KNN) lead-free piezoelectric materials have been studied extensively in the past decade. Significant progress has been made in this field, manifesting competitive piezoelectric performance with that of lead-based, for specific application scenarios. Further understanding of the relationship between high piezoelectricity and microstructure or more precisely, ferroelectric domain structure, domain wall pinning effect, domain wall conduction and local polarization switching underpins the continuous advancement of piezoelectric properties, with the help of piezoresponse force microscopy (PFM). In this review, we will present the fundamentals of scanning probe microscopy (SPM) and its cardinal derivative in piezoelectric and ferroelectric world, PFM. Some representative operational modes and a variety of recent applications in KNN-based piezoelectric materials are presented. We expect that PFM and its combination with some newly developed technology will continue to provide great insight into piezoelectric materials and structures, and will play a valuable role in promoting the performance to a new level.