森田 昇

Light is able to remotely move matter. Among various driving forces, laser-induced metal sphere migration in glass has been reported. The temperature on the laser-illuminated side of the sphere was higher than that on the non-illuminated side. This temperature gradient caused non-uniformity in the interfacial tension between the glass and the melted metal as the tension decreased with increasing temperature. In the present study, we investigated laser-induced metal sphere migration in different glasses using thermal flow calculations, considering the temperature dependence of the material parameters. In addition, the velocity of the glass flow generated by the metal sphere migration was measured and compared with thermal flow calculations. The migration velocity of the stainless steel sphere increased with increasing laser power density; the maximum velocity was 104 mu m/s in borosilicate glass and 47 mu m/s in silica glass. The sphere was heated to more than 2000 K. The temperature gradient of the interfacial tension between the stainless steel sphere and the glass was calculated to be -2.29 x 10(-5) N/m/K for borosilicate glass and -2.06 x 10(-5) N/m/K for silica glass. Glass flowed in the region 15-30 mu m from the surface of the sphere, and the 80-mu m sphere migrated in a narrow softened channel.

The purpose of this study is to develop novel cutting tools with micro- or nanoscale textures on their surfaces. Texturing micro- or nanoscale features on a surface allows us to control the tribological characteristics of the tool. For this research, textures were applied to end mills with a diameter of 0.5 mm using a femtosecond laser, and milling experiments were conducted on aluminum alloy to evaluate the developed tools. The applied texture decreased the cutting forces. This effect depends on the shape of the texture: groove textures are more effective for reducing friction and the resultant cutting forces. Periodic textures fabricated through the interference of the laser were effective at reducing the adhesion of the work material. A larger effect was obtained for shallow and large pitch textures. The results indicate that the proposed method is effective at improving the machining performance of small-diameter end mills.

In this research, we investigated both the etching characteristics of the non-diamond phase induced by focused ion beam (FIB) irradiation and the patterning method of shallow multiple depth structures. FIB irradiation on the diamond surface induces a non-diamond phase, and this area can be selectively etched by heating in air. The dependence of the shape on the FIB and heating conditions was investigated. Process temperatures equal to or lower than 600 degrees C were effective for structure fabrication in terms of the fine shape of the structure. The removal depth can be controlled by varying the ion fluence and ion energy. The process temperature and heating time were important factors for determining the depth range and etch rate. The shape of the structure was affected by the morphology of the FIB-induced non-diamond phase, and the maximum etching depth was dependent on the defect density induced by FIB irradiation. Concave multiple-depth structures with depths of several tens of nanometres were fabricated based on these results, indicating the possible use of this method for shallow multiple depth patterning on diamond surfaces. (C) 2016 Elsevier B.V. All rights reserved.

In this paper, we describe curved hole drilling via the reflection of a laser beam off the sidewall of the drilled hole. A slightly offset laser beam forms a tilted surface at the bottom of the hole, controlling the angle of curvature. An ultraviolet laser beam operating at a wavelength of 266 nm was used. To visualize the hole formation process, borosilicate glass was used as the laser workpiece. This method was able to drill a curved hole with an average angle of similar to 3 degrees with curvature beginning at a depth of 400-600 pm. A curved hole with a diameter of <50 mu m was achieved. A branched hole was also demonstrated by using the reflection of the tilted sidewall. The curved hole formation process was recorded with a high speed camera. Once the ablated sidewall reached a certain depth, drilling ceased as the laser energy fell below the ablation threshold. Ultimately, judicious selection of an appropriate laser fluence and sidewall angle allow the formation of curved holes. (C) 2016 Published by Elsevier Inc.

We propose a novel method for drilling of silica glass based on the continuous-wave laser backside irradiation (CW-LBI) phenomenon. The method allows drilling to be performed by single-shot irradiation using a CW laser. A spindle-shaped emission is generated in the bulk glass and is then guided to the glass surface, and at the instant that the beam reaches the surface, the glass material is ejected. The glass ejection process occurs for a time of similar to 250 mu s. A hole that is similar in shape to that of the spindle-shaped emission is left. The hole length tended to increase linearly with increasing laser power. The laser power dependence of the spindle-shaped emission propagation velocity is also linear, and the velocity increases with increasing laser power. The hole diameters were smaller in the case where the laser focus position was set on the glass surface, and these diameters increased with increasing defocusing. The maximum hole depth reached more than 5 mm. Through-hole drilling was demonstrated using a 3-mm-thick glass substrate.

The formation of a monocrystalline silicon needle by picosecond optical vortex pulse illumination was demonstrated for the first time in this study. The dynamics of this silicon needle formation was further revealed by employing an ultrahigh-speed camera. The melted silicon was collected through picosecond pulse deposition to the dark core of the optical vortex, forming the silicon needle on a submicrosecond time scale. The needle was composed of monocrystalline silicon with the same lattice index (100) as that of the silicon substrate, and had a height of approximately 14 mu m and a thickness of approximately 3 mu m. Overlaid vortex pulses allowed the needle to be shaped with a height of approximately 40 mu m without any changes to the crystalline properties. Such a monocrystalline silicon needle can be applied to devices in many fields, such as core-shell structures for silicon photonics and photovoltaic devices as well as nano- or microelectromechanical systems.

Texturing on the surface of cutting tools is an effective method to improve the friction and resultant machining performances of the tool. In this study, to fabricate nanotextures on various tools used for precision cutting, a patterning method on nano-polycrystalline diamond and cubic boron nitride tools was investigated using focused ion beam (FIB) irradiation and heat treatment. Patterning was possible using this method, and the patterning characteristics were different from those of single-crystal diamond. This method was more suitable for cutting tools compared with direct FIB machining because of its high efficiency and significantly low affected layer.

A micro/nano-scale cutting mechanism using a non-rigid tool holder has been developed. This mechanism, which relies on a control principle that is based on a technique for nano-cutting using an atomic force microscope (AFM), can be used to fabricate grooves with a constant cutting depth on the order of a few micrometers. A linear displacement sensor is used to measure the deformation of a flexible cantilever beam to which a single-crystal diamond tool is attached. This sensor, operated in conjunction with a feedback control system and piezoelectric actuator, can maintain a constant normal cutting force during the machining process. Unlike other nano-cutting systems, this system is attached to a common machine tool that increases its machining area to a couple of square centimeters, which is required for practical applications. Several experiments were performed using this cutting mechanism to assess its performance during the cutting process, especially when the grooves are fabricated on inclined or curved surfaces without a prior knowledge of the surface geometry. (C) 2015 Elsevier Inc. All rights reserved.

There have been many investigations into the changes in the properties of transparent materials, e.g. optical, physical and chemical properties, induced by focused ultrafast laser beams. In this letter, we report the modification of borosilicate glass using an ultraviolet nanosecond laser. A laser beam operating at a wavelength of 266 nm was focused inside the glass. Interestingly, although penetration depth of the laser beam was only 110 μm, emission was observed in the glass at the depth of approximately 1100 μm after several laser shots. The emission moved toward the light source with further laser illumination, and modification of the glass along the trajectory of the emission was observed. The modified area became deeper with increasing focusing depth. The deepest modified area was located at a depth of approximately 1800 μm. No clear dependence of the modification on the pulse repetition rate was found; therefore, heat accumulation was not prominent in the modification process. The subsequent etching rate of the modified area was faster than that of the unmodified area. The etching rate in aqueous KOH was 60 μm/h where continuous modification was obtained. A microchannel with a depth of approximately 400 μm and a diameter of approximately 30 μm was formed after 10 h etching.

The distribution of dynamic stress in sheet glass, stress which is caused by a continuous step input from a cylindrical loader, was estimated by considering elastic wave propagation. In modeling the dynamic stress behavior, we used a two-dimensional dynamic stress model combining a plane stress model and the equations of motion. A finite-difference method was used in the numerical calculation. Under damped vibration mode conditions, the dynamic stress behavior in the sheet glass was investigated in both the depth (Z) and horizontal (X) directions. The stress component in the Z direction changed from tensile to compressive near the outside glass surface of the contact stress distribution. The stress component in the X direction changed from compressive to tensile in the Z direction under the glass surface at the center of the contact stress distribution. The overshoot of the dynamic stress in the Z direction was 1.8 times that of the steady stress during an elapsed time of less than 1 ns from the beginning of loading.

Photoelasticity is a method that enables experimental stress analysis in transparent materials by analyzing the photoeleastic fringes. In this paper, we propose a method to estimate phase difference correctly when the experimental stress is increased monotonously. The point of turning over the phase difference was estimated and photoelastic fringes were counted automatically. The developed program counted phase difference correctly.

A non-rigid cutting mechanism was developed to apply a technique to control the normal cutting force during the fabrication of micro-grooves. Although this mechanism has been mainly used for ductile materials, several experiments on glass were performed as result the fabrication of crack-free micro-scale grooves was achieved. The photoelastic analysis was applied to observe the internal stress field on the material during the cutting process comparing the non-rigid mechanism and a rigid tool-holder. The critical cutting depth using this mechanism was determined in approximately 2.5. μm and some of the cutting conditions were defined in order to achieve ductile mode cutting.

We present numerical and experimental studies of heat accumulation during high-aspect-ratio ultraviolet laser microdrilling of glass. The dependence on pulse repetition rate of the ablation threshold was studied. The rate determines the amount of heat accumulation and temperature variation across the illuminated area. No change in the glass was observed for pulse energies below 1 A mu J at 1 kHz; melting occurred at 0.3 A mu J, with ablation at 0.7 A mu J at 20 kHz. Also, the hole depth doubled when the pulse repetition rate was increased from 1 to 20 kHz. Moreover, the fluence of 4 J/cm(2) that passed through drilled holes at 1 kHz decreased to 1 J/cm(2) at 20 kHz.

Techniques to control the colors and properties of glasses based on doping of the glasses with various metals and nanoparticles are widely used. In this paper, we demonstrate the migration of a nickel sphere in silica glass caused by laser illumination accompanied by nickel nanoparticle precipitation in the sphere migration trajectory. During migration, the diameter of the nickel sphere decreased. Precipitated nanoparticles with diameters of several hundred nanometers were observed in areas of up to 50 mu m in radius and these nanoparticles formed four cylindrical coaxial layers with stripes at 10-20 mu m intervals in the migration direction. (C)2015 Optical Society of America

Nano-machining requires precise positioning of a tool on a work piece when the tool is exchanged during the machining. But the usual positioning accuracy is 1 μm or less. In this report we propose a method to detect the relative position of a tool and a work piece by 10 nm order repeatability. For this positioning, low voltage is supplied between the tool and the work piece, and the contact position of the tool and the work piece is detected from the current variation between them. The voltage and the current is restricted at the level of Scanning Tunneling Microscope (STM). This method has a possibility that the positioning process is done without contact of them, because the detected current is the tunnel current. Experimental results by the fundamental test show that the repeatability of positioning is less than 20nm.

In this study, we propose a novel method of sub-micrometer-scale patterning on a single crystal diamond surface using a combination of focused ion beam (FIB) and deep ultraviolet (DUV) laser irradiations. We found that the diamond surface area irradiated by the FIB could be selectively machined by low-power DUV laser irradiation, whereas the non-FIB-irradiated area was barely machined. Therefore, sub-micrometer-scale patterning is possible using selective laser removal of the FIB-irradiated area. To investigate the machining characteristics in this process, the effect of the Ga removal step and the DUV laser irradiation conditions was investigated. As a result, the shape of the DUV-irradiated area was improved by applying the Ga removal step, and debris was not observed. In addition, the maximum structure depth was 83 nm and was determined by the damage density induced by the FIB this is more than twice the depth of that fabricated using the heating technique in air.

The crack propagation behavior and the internal stress field during mechanical cleavage of non-alkali glass sheets (thickness : 0.7mm) were visualized by high-speed imaging techniques. At first, the effect of scribing conditions on the fractured surface quality was investigated when the scribing wheel with surface asperities was used. It was found that the surface quality was strongly influenced by an applied load. In the case of low load conditions (∼11N), the fractured surface exhibited rugged patterns known as 'hackle', and it gradually changed to regular striped pattern known as 'ribmark' with the increase of applied load (12N∼). In order to understand the reason why the surface quality changed with the applied load, the crack propagation behavior was observed using a high-speed camera. The results showed that the generated crack hardly propagated to thickness direction when the applied load was low, in contrast to the rapid propagation under the high load conditions. Because the crack propagation behavior was likely determined by the stress field around the generated crack, the phase difference measurement, which was proportional to the principal stress difference, was conducted using a high-speed polarization camera. The results showed that the phase difference gradually vanished, i.e. the stress relaxation occurred, with the crack propagation especially in the high load conditions. By the image analysis for obtained phase difference from the polarization camera, an in-process estimation method of fractured surface quality was proposed.

A new cutting mechanism for the fabrication of microscale grooves is presented in this study. Based on the control principle of the nano-cutting mechanism using an Atomic Force Microscope (AFM), in the newly developed system, a single crystal diamond tool is mounted at the free edge of a cantilever beam and is used for the removal of material. During the cutting process, the cantilever undergoes a deformation that is required for the implementation of a machining force feedback control. It was experimentally observed that the use of this mechanism enables to maintain the cutting depth of the micro-grooves constant even if they are fabricated on inclined surfaces this is achieved by maintaining the normal cutting force constant using a feedback controller. For this experimental system, an optical lever is used to measure the angular deformation at the tip of the cantilever, thus providing a better understanding of total cutting force involved in the machining process.

The dynamic thermoelastic behavior of a sheet glass subjected to single-pulse laser irradiation is clarified using a one-dimensional model. From the equation of motion for this system, a thermoelastic equation was derived and applied in the analysis. For a 0.1-μs pulse duration, the displacement and thermal stress caused by the thermal expansion within the slab show oscillatory wave characteristics. When thermal stress waves are reflected at the free ends of the sheet glass, the polarity of the stress changes. Alternating stress waves of approximately 0.5-MHz frequency appear in the slab. With cracks propagating in the glass as a result of stress, high-cycle fatigue is possible. We confirm that the dynamic behavior generated by single-pulsed laser irradiation features wavelike properties.

We describe a technique to improve diamond cutting tools used in nanometer- and micrometer-scale machining and formed via focused-ion-beam (FIB) micromachining. Although FIB irradiation is an effective means of fabricating arbitrary miniature shapes in diamond cutting tools, FIB irradiation induces a non-diamond phase, as well as Ga ion implantation, in the irradiated area. This adversely affects the performance of the ultra-precision machining process, especially in terms of tool life and the quality of the machined surface. To eliminate the affected layer, we applied heat-treatment techniques and investigated the optimum thermal profiles. A temperature of 500 degrees C applied to the cutting tool provided optimal machining of nickel phosphorus. The tool life was significantly improved, and a tool life similar to that of a non-irradiated diamond tool was obtained. The quality of the machined surface was also improved markedly owing to superior tool wear and adhesion resistance. (C) 2014 Elsevier B.V. All rights reserved.

In our previous paper, we incorrectly calculated the total applied force on the metal particle. We have corrected the results and the affected figures. These corrections do not affect the conclusions of the published paper. (C) 2014 Optical Society of America

Using electric-field-assisted solid-state ion exchange, we formed a buried silver nanowire network in borosilicate glass. This procedure had two stages: a silver doping stage by applying voltage with silver as the anode (referred to as forward) and a silver precipitation stage by applying voltage in the opposite direction (referred to as reverse). Microscopic observations revealed many needle-like precipitates (100-300 nm in diameter) linked to each other, forming a thin layer at the bottom of the silver-doped area. The configuration of the layer formed in the glass matrix was precisely transferred from that of the dopant, silver foil in the present study. The embedded electrical wiring in the glass slide was tested using a patterned circuit-like silver foil as a dopant. Measuring the electrical resistance between two ends of the formed wire, we found that the embedded layer had high conductivity and acted as an electrical circuit. (C) 2014 AIP Publishing LLC.

A focused ion beam (FIB) is an effective means of fabricating micro- to submicro-scale shapes on diamond cutting tools. However, ion irradiation of diamond tools causes ion implantation, defects, and non-diamond phases, all of which degrade the tool performance. To remove affected layers from FIB-irradiated diamond tools, heat treatment in air was applied, and the effect of the heating parameters on the etchability of the irradiated area was investigated. It was found that the affected layer could be etched and removed from the diamond tool surface, even at 500 °C. In machining experiments on aluminum alloy and nickel phosphorus, machining performance was improved by the applied heating technique, and the cutting forces and machined surfaces were similar to those obtained with the non-irradiated tool. These results indicate that the proposed heating technique is effective for diamond cutting tools shaped by FIB.

本研究では，原子間力顕微鏡（AFM）機構と加工用AFMカンチレバーを用いて，高能率な微細加工を行うことを目的としている．本報では，1本のカンチレバーに複数の多結晶ダイヤモンド切れ刃を具備した多刃カンチレバーと，剛性の異なるカンチレバーを複数本有するマルチカンチレバーの2種類の加工用AFMカンチレバーを作製し，Ni-P合金めっきと単結晶シリコン(100)に対して加工実験を行い，高能率微細加工用工具としての評価を行った．その結果，多刃カンチレバーは，複数の切れ刃による同形状の同時加工が可能であった．また，マルチカンチレバーはたわみ剛性に応じた同時加工が可能であった．

本研究では，原子間力顕微鏡（AFM）機構と加工用AFMカンチレバーを用いて，微細かつ高精細なV溝加工を行うことを目的としている．本報では，集束イオンビームを用いて，ダイヤモンド切れ刃の先端角，すくい角，横すくい角を設けた加工用AFMカンチレバーを作製し，Ni-P合金に対して溝加工実験を行い，切れ刃形状が加工溝性状に及ぼす影響について検討を行った．その結果，先端角35°，すくい角0°の切れ刃を有する加工用AFMカンチレバーは，切れ刃断面形状を精度よく転写した微細V溝加工が可能であった．さらに，正の横すくい角を設けることにより，加工溝の盛り上がりを低減させることができた．

Tool shape is an important factor determining the shape and accuracy of machined areas in ultra-precision machining. Use of a focused ion beam (FIB) is an effective means to fabricate micro- to submicro-scale tool shapes. However, ion irradiation causes doping and defects in the tool that reduce tool performance. To use FIB machining on a single-crystal diamond tool without degrading tool performance, a combination of 500 degrees C heat treatment and aluminum deposition was used to remove gallium (Ga) ions induced by ion irradiation. The method was evaluated through machining experiments that showed that irradiation of Ga ions causes work materials to adhere to the tool surface. This adhesion and the resulting rapid tool wear were reduced by heat treatment. The proposed method also improved the transcription ability and wear resistance of the tool so it was capable of producing a surface quality better than or equal to that produced by non-irradiated tools, even over long cutting distances. (C) 2013 Elsevier Inc. All rights reserved.

Metal (silver or copper) ions were doped into borosilicate glass using an electric field-assisted ion exchange method. The optical transmittance of the metal doped glass was measured to determine why the doped glass exhibited an excellent laser micro-machinability. The doped metal ions were found to have enhanced the optical absorption of the glass, especially in the ultraviolet range. This in turn facilitated the efficient absorption of incident laser irradiation, and hence improved laser machinability of the glass. The metal doped glass also exhibited some absorption in the visible range, leading to a slight yellow-brown coloration. Transmission electron microscope (TEM) observations indicated that the metal ions had penetrated the glass and therein formed nanometer-sized (similar to 6 nm) fine particles. In an attempt to control the optical characteristics in the ultraviolet-visible range, metal doped glass was heat-treated following the ion exchange doping step. In the case of silver-doped glass with heat treatment at 723 K, silver nanoparticles aggregated locally yielding an inhomogeneous structure. The heat-treated samples had a high optical absorption in the ultraviolet range.

The thermoelastic behavior of sheet glass during laser irradiation was clarified using a one-dimensional model. A thermoelastic equation based on an equation of motion with the damping force proportional to the deformation velocity was applied. The thermal and thermoelastic equations were numerically solved by the finite difference method based on an implicit method for the time evolution. A proportional damping coefficient (PDC) was adopted for the calculation. In the case of a stationary heat source, compressive stress on the heated region changed into tensile stress 0.1 s after the end of heating. In the case of a moving heat source, the highest tensile stress was induced when the PDC was less than 0 1 An optimal combination of velocity and the PDC that induced the maximum tensile stress was obtained.

In this study, we propose the new equations which predict cutting forces under the conditions of a small feed (2.5μm) and negative approach angle. They are based on Nakayama's equations. According to our previous research, the experimental cutting forces were larger than the calculated forces with Nakayama's equations. The differences were caused by size effect. One of the causes of size effect was a cutting edge radius. Therefore, the new equations were formulated with taking into account the cutting edge radius. The cutting force calculated by the new equations were approximately equal to the experimental results. The accuracy of the new equations is validated under the conditions of thrust force free cutting.

本研究では，ガラス管を用いて，穴底部にレーザ光と水を同時に供給する穴あけ法を開発した．ガラス管の一端にレーザ光と水を供給すると，レーザ光はガラス管内を全反射し，ガラス管の反対側端面から水と同時に加工部に照射される．穴への管の挿入で，穴底部へ高エネルギの光の照射が可能になる．また，水を流すことで，デブリの排出も容易となる．実験装置の試作およびガラス管内をレーザ光を効率よく導波させるために導波解析を行った．本手法により，天然ゴムに穴径2.0mm，穴深さ30mmの穴加工を行った．また，曲がったガラス管を用いることで，曲がり穴加工を実現した．

本研究では，卓上精密旋盤を用いて形状精度の高い微細軸を作製する手法について検討した．旋削加工を行う際に生じる切削力のうち，背分力は軸の寸法や形状精度に影響を及ぼす．旋削条件のうち，工具のノーズ半径，アプローチ角および切込み量を適切に設定することで背分力を抑制する加工条件について検討した．その結果，背分力をゼロに抑制することが可能であることを示し，軸径50μm，長さ1mmの微細軸を旋削加工により作製することが可能であることを示した．また，切削抵抗に関する実用式と実験結果の比較を行い，その差異の要因について検討した．

We optically manipulated a metal particle in borosilicate glass. The glass in the neighborhood of the laser-heated metal particle softened; hence, the metal particle was able to migrate in the glass. In this letter, the driving force of the metal particle toward the light source in the glass provided by laser illumination was investigated. The variation in the surface tension of the glass at the interface between the glass and the metal particle induced by the temperature gradient was calculated via a numerical temperature calculation. It was found that the temperature at the laser-illuminated surface of a stainless-steel particle with a radius of 40 mu m was similar to 320 K higher than that on the nonilluminated side. The force applied to the metal particle from the surrounding glass was calculated to be similar to 100 mu N, which was approximately equal to the viscous resistance force. In addition, the experimental and numerically calculated speeds of the moving particle, which was measured while varying the laser power, are discussed. (c) 2013 Optical Society of America

In order to improve the laser micro-machinability of borosilicate glass, the glass surface was doped with metal (silver or copper) ions by electric field-assisted solid-state ion exchange. Doped ions drifted and diffused into the glass substrate under a DC electric field. The drift-diffusion behavior of metal ions in glass was numerically analyzed using standard explicit finite-difference method. The calculated penetration depths of both silver and copper showed good agreement with experimentally measured values. However, there was a difference between measured and calculated ionic fluxes, especially for the early-stage of ion exchange. This discrepancy was likely to be caused by an imperfect initial contact between metal foil and glass substrate. Therefore, the increase in electric current path with ion exchange time was necessary to be taken into consideration. The modified calculation enabled more accurate estimation of ionic penetration depths.

単結晶ダイヤモンドの工具を用いて硬脆材料を延性モード切削すると，激しい工具摩耗が発生する¹⁾．光学ガラスの延性モード切削においても同様である²⁾．この工具摩耗は逃げ面に発生し，被削材との摩擦が主因であると考えられる．単結晶ダイヤモンドとBK7ガラス円を用いた摩擦摩耗実験を行い，摩耗原因の解明を試みた．実験では摩擦速度，押付荷重などの摩擦条件による摩耗量を比較した．その結果，摩擦速度，押付荷重の増加に伴い摩耗量は増加した．BK7の摺動面からは，グラファイトが検出された．また，同一条件におけるBK7，アルミナ，サファイヤでの摩耗量および摩擦温度の比較をした．その結果，BK7が最もダイヤモンドを摩耗させ，摩擦温度も高かった．ダイヤモンドと硬脆材料との摩擦時には発光が観察される．この発光を分光した結果，紫外光を主とするトライボマイクロプラズマであることがわかった．

In order to research effect on the cutting performance for aluminum alloy by mixing isopropyl alcohol (IPA) and water, the performance of IPA aqueous solution was compared with IPA and water by the sliding test, cooling test and cutting test. Consequently, it was found out that IPA aqueous solution provided the best cutting performance in the cutting fluids. The sliding test between aluminum alloys revealed that IPA aqueous solution has a function that suppresses the adhesion of aluminum alloy. It seems that the adhesion on the tool decreased by this function. The cooling test of heated test pieces showed that the cooling ability of IPA aqueous solution was higher than that of IPA. Because of high cooling ability, the chip in cutting with IPA aqueous solution mist might curl smaller than that in cutting with IPA mist.

本研究では，卓上精密旋盤を用いて形状精度の高い微細電極を作製する手法について検討した．旋削加工を行う際に生じる切削力のうち，背分力は電極の寸法や形状精度に影響を及ぼす．旋削条件のうち，工具のノーズ半径，アプローチ角および切込み量を適切に設定することで背分力を抑制する加工条件について検討した．その結果，背分力をゼロに抑制することが可能であることを示し，電極径50μm，長さ1mmの微細電極を旋削加工により作製することが可能であることを示した．また，作製した微細電極を用いて放電加工を行い，微細孔を形成した．

A photomask for semiconductor device production faces serious problems related to the thermal displacement of the mask pattern during exposure. During mask exposure, pattern placement error occurs in the mask. The minimization of thermal in-plane displacement is needed. To estimate thermal displacement, a model based on the three-dimensional steady-state thermal theory and two-dimensional in-plane stress theory was proposed by the finite difference method. Three types of boundary condition, that is, a free edge, a fixed edge, and a combination of a free edge and a fixed edge were investigated to minimize mask pattern placement error. Quantitative relations of the boundary condition and thermal displacement were clarified. It was found that the fixed edge minimizes pattern placement error caused by thermal expansion. Moreover, the combination of the free and fixed edges indicated the directionality of the placement error distribution.

A laser forward transfer technique of gold nanoparticles (GNPs) deposited on glass substrates to silicon wafers and periodic patterning of transferred GNPs is demonstrated. Gold colloidal solution was prepared by citric acid reduction method. The GNPs were deposited by immersing glass substrates derivatized with (3-aminopropyl) trimethoxysilane (APTMS) in the gold colloidal solution for 0.5 h - 3 h. Dispersed or aggregated GNPs were deposited by using Gold colloidal solution with different concentrations. The glass substrate deposited with the GNPs was placed on a Si substrate. The GNPs deposited side was faced to the Si substrate. Then GNPs were illuminated with the second harmonic wave of Nd: YAG laser through the glass, as a result the gold nanoparticles were transferred to the Si substrate. The GNPs deposited on the silicon surface was sphere and dispersed, nevertheless, they were aggregated on the glass surface before transferring by the laser illumination. After the illumination of the Nd: YAG laser to the silicon surface with the GNPs, the periodic deposition of Au was observed. The periodic spacing of the Au were depended on the wavelength and incident angle of the laser beam.

試作した2次元切削可視化装置を用いて，工具形状および切削条件がCFRP材料の被削性に与える影響について検討した．2次元切削可視化装置をCFRP材料用に改良し，工具形状および切削条件を変化させ，切削抵抗測定，加工面観察，切りくず観察，切削挙動観察を行い，CFRP材料の加工時の切削現象の特異性を明らかにするとともに，CFRP加工に適した工具形状を提案した．