• Current Optics and Photonics
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• 제5권3호
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• pp.229-237
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• 2021

The capabilities of the near-field scanning optical microscope (NSOM) for obtaining high resolution lateral topographical images as well as for mapping the spectroscopic and optical properties of a sample below the diffraction limit of light have made it an attractive research field for most researchers dealing with optical characteristics of materials in nano scales. The apertured NSOM technique involves confining light into an aperture of sub-wavelength size and using it to illuminate a sample maintained at a distance equal to a fraction of the sub-wavelength aperture (near-field region). In this article, we present a setup for developing NSOM using a cantilever with a sub-wavelength aperture at the tip. A single laser is used for both cantilever deflection measurement and near-field sample excitation. The laser beam is focused at the apex of the cantilever where a portion of the beam is reflected and the other portion goes through the aperture and causes local near-field optical excitation of the sample, which is then raster scanned in the near-field region. The reflected beam is used for an optical beam deflection technique that yields topographical images by controlling the probe-sample in nano-distance. The fluorescence emissions signal is detected in far-field by the help of a silicon avalanche photodiode. The images obtained using this method show a good correlation between the topographical image and the mapping of the fluorescence emissions.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2002년도 마이크로/바이오 가시화기술부문 학술강연회
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• pp.1-7
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• 2002

This papers describes the preparation and experimental results of a micro mass detection devices based on cantilever and a diffuser-type micro pump using screen printing thick-film technologies and Si micro-machining. PZT-PCW thick films were prepared by new hybrid method based on the screen printing. By applying these PZT-PCW piezoelectric thick films on actuator, a cantilever for mass detection sensor and a micropump for microfluidic element are successfully fabricated. Resonant frequency and displacement of PZT-PCW thick film actuator in air and in liquid are measured by laser vibrometer system as a function of actuator size. The resonant frequency of PZT-PCW thick film actuator in liquid decreases order of 1/2-1/4 due to damping effect. The sensitivity of cantilever is characterized by Au deposition method which has the mass loading effect such as adsorption of protein. The Sensitivity of PZT-0.12PCW thick film cantilever is proportional to detecting area.

• 동력기계공학회지
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• 제13권3호
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• pp.65-71
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• 2009

This paper presents the energy harvesting technique which is carried out by vibration system with a piezoelectric element. In this study, low frequency characteristics of the piezoelectric element bonded to the aluminum cantilever were experimentally investigated. The piezoelectric element of size of $45L{\times}11W{\times}0.6H$ and piezoelectric constant($d_{31}$ ) of $-180{\times}10^{-12}C/N$ was used. The material of cantilever is an aluminum and two kinds of cantilever of which dimensions are (150, 190)$[mm]{\times}13[mm]{\times}1.5[mm]$ were experimented, respectively. The cantilever was fixed on the magnetic type vibrator and the vibrator was operated by power input with a sine wave. The characteristics of requency and mass variation of cantilever end part such as 0, 2.22, 4.34, 5.87, 8.66, 11.01 [g] were investigated. Finally, this paper suggests a method of generating electrical energy with a piezoelectric element using wind, an energy source that is easily applied and from which we can obtain "clean" energy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.248-252
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• 2009

Purpose: This retrospective study was performed to analyze the relationship between complications of the posterior mandibular single crowns and distance from the adjacent teeth to the implant. Subjects and Methods: Of the patients who presented Ewha Womans University Mokdong Hospital & Yonsei University Dental Hospital with missing of the posterior mandibular molar and restored with implant-supported 18 Single crowns between 1996 thru 2007, 115 patients had been followed after crown delivery. The subjects were divided into complication-followed group and a control without any problems. The distance from the most distal tooth to the implant were measured. The prosthetic & biologic complications were reviewed by the cantilever distance and analyzed by abutment type, age & gender statistically using SAS version 9.1 (SAS Inc., USA). Results and Conclusion The results were as follows; 1) The posterior mandibular single crown with cantilever showed higher incidence of follow-up complications upon logistic analysis (p<0.05). 2) The prosthetic and biologic complications are related with the cantilever distance with 2.1 odds ratio and 3.39 cut-off value of specificity & sensitivity by SPSS 12.0. 3) The complications are neither significant in abutment types nor age & gender.

• Journal of Periodontal and Implant Science
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• 제23권2호
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• pp.352-357
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• 1993

The purpose of the present study was to evaluate and compare the periodontal conditions of distally extending cantilever bridges(CB) and removable patial dentures(RPD). 78 patients treated with removable partial dentures were divided into 2 groups; bilateral free-ending (type 1) and unilateral free-ending(type 2). 43 patients treated with distally extending cantilever bridges were divided into 4 groups according to position of missing molars and number of including abutment tooth (or teeth) (type 1-4). Prosthodontic status of the abutment teeth were assessed; overcontoured crown, overhanged margin, embrasure closure, and others. Their Periodonted status were assessed with Plaque Index Gingial Index(GI) Sulcus bleedy Index (SBI), Tooth mobility(TM) & Posher depth(PPD). 35.9% of RPD group and 38.1 of CB grouphad disconfort on mastication with prosthetics. 16.7% of RPD group and 6.1% of CB group showed on opposing sites. Overhanged margins were 58.3% for RPD group and 86.6% for GB group. 45.5% of RPD group and 72% of CB group had embrasure closure on the abutment teeth. 30.5% of GB group had oversized pontic. Gb group showed much higher clinical parameters than RPD groups, but statistically not significant. Type 2 of RPD group showed lower GI and SBI, but statistically not significant. Type 3 of CB group showed the highest GI and SBI and type 2 showed the highest tooth mobility, but there is no differences between the same type of groups. In conclusion, only minor differences in periodontal conditions were recorded in RPD and CB group.

• 한국전산구조공학회논문집
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• 제19권4호
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• pp.399-406
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• 2006

황동 개재물이 있는 Al 정사각판의 고유진동수는 혼합법칙을 이용하여 해석되었다. 혼합법칙에 의한 고유진동수는 개재물의 크기에 따른 유효 내평면 파동속도와 무차원 진동수 매개변수와의 곱으로 이루어진다. 해석모델은 외팔형, 2변 고정-2변 자유형, 3변 고정-1변 자유형 및 4변 고정형의 황동 개재물이 있는 4가지의 Al판이다. 자유단이 1개 이상 존재하는 경계조건에서 개재물이 판의 중앙에 위치하였을 때 개재물에 대한 판 전체의 면적비가 1/9 이하이면 혼합법칙 및 유한요소 해석에 의한 고유진동수는 10% 이내로 잘 일치하였다 4변 고정형 경계조건을 제외하고 3가지 경계조건에서 개재물이 판중앙에 있을 경우 개재물의 크기가 커짐에 따라 개재물이 있는 판의 고유진동수는 낮아짐을 알았다. 또한 개재물의 밀도가 판의 밀도보다 작을 때, 개재물 크기가 커짐에 따라 개재물이 있는 판의 고유진동수는 높아진다.

• 한국전기전자재료학회논문지
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• 제25권10호
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• pp.766-772
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• 2012

Spring supported piezoelectric cantilever structures (SPCS) were fabricated for vibration-based energy harvester application. We selected four elastic springs (A, B, C, and D type) as cantilever's supporter, each elastic spring has a different spring constant (S). The C type of SPCS ($S_C$: 4,649 N/m) showed a extremely low resonance frequency of 81 Hz along with the highest power output of 38.5 mW while the A type of SPCS ($S_A$: 40,629 N/m) didn't show a resonance frequency while. Therefore, it is considered that the lower spring constant lead to a lower resonance frequency of the SPCS. In addition, a tip mass (18 g) at one end of the SPCS could further reduce the resonance frequency without heavy degradation of power output.

• 복합신소재구조학회 논문집
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• 제3권2호
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• pp.47-54
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• 2012

In this study, composite laminate cantilever type cylindrical shells with edge-stiffeners are analyzed. A versatile 4-node flat shell element which is useful for the analysis of shell structures is used. An improved flat shell element is established by the combined use of the addition of non-conforming displacement modes and the substitute shear strain fields. Two models by load conditions are considered. Load type A and B are loaded by point load at the free edge and line load respectively. A various parameter examples are presented to obtain proper stiffened length and stiffened thickness of edge-stiffeners. It is shown that the thickness of shell can be reduced minimum 30% by appropriate edge-stiffeners.

• 한국생산제조학회지
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• 제7권2호
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• pp.54-61
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• 1998

This paper examines the crack growth behavior of 7075-T651 aluminum alloy for small tensile overload under high-low block loading condition. The cantilever beam type specimen with a chevron notch is used in this study. The crack growth and closure are investigated by compliance method. The applied initial stress ratios are R=-0.5 R=0.0 and R=0.25 Crack length, effective stress intensity factor range, ratio of effective stress intensity factor range and crack growth rate etc, are inspected with fracture mechanics estimate.

• ETRI Journal
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• 제27권4호
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• pp.433-438
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• 2005

We present a new type of silicon micro-probe card using a three-dimensional probe beam of the cantilever type. It was fabricated using KOH and dry etching, a porous silicon micromachining technique, and an Au electroplating process. The cantilever-type probe beam had a thickness of $5 {\mu}m$, and a width of $50{\mu}$ and a length of $800 {\mu}m$. The probe beam for pad contact was formed by the thermal expansion coefficient difference between the films. The maximum height of the curled probe beam was $170 {\mu}m$, and an annealing process was performed for 20 min at $500^{\circ}C$. The contact resistance of the newly fabricated probe card was less than $2{\Omega}$, and its lifetime was more than 20,000 turns.