Two-photon Microstereolithography Research Articles

Development of a two-photon microstereolithography system with an autofocus function

Development of a two-photon microstereolithography system with an autofocus function

レーザー誘起マイクロバブルによるマイクロマシンの駆動と制御

In this study, we have realized the control of a microrotor using the convection flow around a laser-induced microbubble. To examine the rotation of the microrotor, the temperature distribution and the convection flow around the microbubble were analyzed by finite element analysis. As a result, it was found that the flow direction depended on the position of a microbubble. This phenomenon makes it possible to control the rotational direction of the microrotor. In experiments, a microrotor and two thin plates were fabricated on a glass substrate by two-photon microstereolithography and subsequent electroless copper plating. It was demonstrated that the rotational direction of the microroter was switched by changing the position of the laser-induced bubble. The bubble-driven micromachines will be useful for microfluidic devices such as micropumps and micromixers.

F221005 マイクロ・ナノ光造形・鋳型技術の開発とその応用

Microstereolithography has been widely applied for a lot of applications such as photonics, MEMS and lab-on-a-chip. The remaining issues of microstereolithography are improvement of both throughput and material limitation. To overcome these issues, we have developed soft and hard molding processes based on one- and two-photon microstereolithography. By using the soft molding process with silicone mold, movable micromachines can be replicated. In addition, the hard molding using a polymeric mold can produce ceramic three-dimensional microdevices such as microchannels, scaffolds, and piezoelectric energy harvesters. These molding processes based on microstereolithography will be useful for mass production of practical devices using various kinds of ceramic materials.

2A1-G26 光造形マルチモールディングの研究 : (第3報)2光子マイクロ光造形法を用いた3次元シリカ構造体の形成

A three-dimensional (3D) molding process based on two-photon microstereolithography and floc casting was proposed and developed to fabricate 3D ceramic microstructures. In this method, a 3D polymeric mold fabricated by two-photon microstereolithography is covered with ceramic slurry and then thermally decomposed to obtain real 3D ceramic microstructures. In this study, a highly concentrated slurry containing submicron fused Si02 particles was used to fabricate transparent Si02 glass microstructures. Thermal decomposition of a photopolymer was examined by thermogravimetry and differential thermal analysis (TG-DTA). The temperature profile of the heating process is optimized using the master decomposition curve (MDC) theory to reduce the number of harmful cracks during thermal decomposition. It was demonstrated that a transparent fullerene-like model and spiral model could be fabricated by the optimized thermal decomposition.

2A1-G14 2光子造形による光電駆動マイクロシステムの開発

2A1-G14 2光子造形による光電駆動マイクロシステムの開発

2A1-J03 マイコプラズマ・モービレを駆動源とするマイクロモータの研究

Bio-microactuators using molecular motors, the cells, and the bacterium are promising micro/nano actuators for MEMS/NEMS application. In this study, we developed a micromotor driven by a bacterium(Mycoplasuma mobile). In our method, microbeads are attached to Mycoplasma mobiles for efficient force transmission from Mycoplasma mobiles to the rotor. The microrotor was fabricated by two-photon microstereolithography. A guide microchannel was fabricated around the microrotor to conduct a Mycoplasma mobile to the microrotor. It was demonstrated that the microrotor was actually rotated by collision of a Mycoplasma mobile with a microbead.

2P1-M02 ラゲールガウスビームを用いた光駆動マイクロマシンの開発

Recently, Laguerre-Gaussian beam (L. G. beam) attracts interest because of its ability to generate orbital angular momentum. The angular momentum enables to rotate multiple microparticles simultaneously just by irradiating the laser beam. In this study, we developed an optical manipulation system using a L. G. beam as a driving source. In our system, a spatial light modulator is used to convert from Hermite-Gaussian beam (H. G. beam) into L. G. beam by giving azimuth direction phase distribution. By using this system, we first examined the driving performance of multiple microparticles by changing the conditions of L. G. beams. Next, we fabricated some types of microrotors driven by the L. G. beam by two-photon microstereolithography. Furthermore, we improved driving performance of the microrotors by changing the shape of rotor. Finally, we made prototype of a viscous micropump driven by the L. G. Beam.

Optically Driven Micromanipulators with Rotating Arms

We propose optically controlled micromanipulation tools that operate in sealed environments. The micromanipulator arm has probes to grasp microobjects and a handle to rotate the arm on its long axis. When a laser beam is focused on the handle and scanned linearly on the focal plane, the handle inclines toward the focus, rotating the arm on its long axis for probes to grasp a microobject. Rotation enable the microobject to be grasped separately from a substrate. Micromanipulators, fabricated by using two-photon microstereolithography, can catch microparticles in three dimensions, and a single manipulator arm with twin probes has been used to slide a microparticle on a glass substrate. Such optically controlled micromanipulators are potentially versatile, powerful tools for micro total analysis in biological applications.

4224 2光子マイクロ光造形による光駆動マイクロポンプの開発(J24-2 生産機械のマイクロ化(2))

4224 2光子マイクロ光造形による光駆動マイクロポンプの開発(J24-2 生産機械のマイクロ化(2))

1P1-N03 光駆動ローリング機構を用いたマイクロマニピュレータの開発(MEMSとナノテクノロジー)

We propose a novel type of optically controlled micromanipulation tools that can work in sealed micro space. The micromanipulator arm has a handle to rotate the arm on its long axis. When a focused laser beam is focused on the handle and scanned linearly in the focal plane, the handle is inclined toward the focus. As a result, the arm is rotated on its long axis. The rolling mechanism allows us to manipulate a microobject stably. The micromanipulators with the rolling mechanism were fabricated by using high-speed two-photon microstereolithography. We demonstrated that the manipulators could catch a microparticle in three-dimensions. In addition, a single manipulator arm was successfully used for sliding a microparticle on a cover glass. Such optically controlled micromanipulators offer versatile and powerful tools for micro total analysis systems for biological applications.

Development of Optically Driven Microgears by Using Two-photon Microstereolithography

Development of Optically Driven Microgears by Using Two-photon Microstereolithography

Micro/nano machining based on two-photon microstereolithography

Micro/nano machining based on two-photon microstereolithography

1P1-C07 エバネッセント場を用いた光駆動マイクロマシンの設計および試作

We have developed a rotary micromachine driven by an evanescent field. The shape of the blades of the rotary micromachine was designed by a numerical simulation based on finite-difference time-domain method. We fabricated a prototype of the rotary micromachine by using two-photon microstereolithography. In a preliminary experiment, we generate an evanescent field by use of total reflection at a surface of a prism to rotate the rotary micromachine. As a result, we demonstrated that the micromachine was rotated by the evanescent field. Such micromachines will be useful for micromixers or micropumps built-in a biochip.

1P1-C02 2光子マイクロ光造形法による光駆動マイクロポンプの開発

1P1-C02 2光子マイクロ光造形法による光駆動マイクロポンプの開発

Effect of low numerical-aperture femtosecond two-photon absorption on (SU-8) resist for ultrahigh-aspect-ratio microstereolithography

We report the quantitative characterization and analysis on the solidification of SU-8, a chemically amplified near-ultraviolet ultrathick resist, based on two-photon-absorbed (TPA) near-infrared photopolymerization. The resolution of TPA photopolymerized SU-8 voxels and lines is studied as a function of laser-pulse energy, single-shot exposure time, and scanning speed. Two-photon microstereolithography using SU-8 as the matrix material was verified by the fabrication of SU-8 photoplastic structures with subdiffraction-limit resolution. We show that the nonlinear velocity dependence of TPA photopolymerization can be used as the shutter mechanism for disruptive three-dimensional (3D) lithography. This mechanism, when combined with low numerical-aperture optics is exploited for the rapid 3D microfabrication of ultrahigh-aspect-ratio (up to 50:1) photoplastic pillars, planes, and cage structures.

Optically-Driven Micro/Nano Machines Produced by Two-Photon Microstereolithography

Optically-Driven Micro/Nano Machines Produced by Two-Photon Microstereolithography

Development of Optically Controlled Micromanipulation Systems by using Two-photon Microstereolithography

We propose optically controlled micromanipulation tools that can work in sealed micro space. The micromanipulation tools constructed with several optically driven micromachines such as manipulators and separators. The optically driven micromachines were produced by high-speed two-photon microstereolithography. The micromachines are simultaneously controlled by an optical trapping technique based on radiation pressure of a focused laser beam. We have developed a laser-scanning manipulation system for the synchronized control of multiple micromachines. By using the manipulation system, we examined the driving performance of the manipulators changing the laser power, scale and thickness of the manipulators. We also evaluated the torque of micromanipulators. In addition, the synchronized driving of micromanipulators and a microseparator were demonstrated in a micro channel. Such cooperative control of optically driven micromachines offers versatile and powerful tools for micro total analysis systems for biological applications.

Complex-shaped three-dimensional microstructures and photonic crystals generated in a polysiloxane polymer by two-photon microstereolithography

Two-photon photopolymerization of inorganic–organic hybrid materials permits the generation of complex-shaped three-dimensional microstructures at submicrometer resolution of structural elements. Due to their favorable optical, chemical and thermal properties these materials are particularly useful for photonic microdevice fabrication. Focussing ultrashort pulsed visible light into a modified commercially available polysiloxane polymer a Sydney Opera House design and a series of woodpile-type photonic crystals were fabricated. Fourier transform infrared spectroscopy revealed photonic stop gaps in the stacking direction at wavelengths varying from 6 to 4 μm upon reduction of the woodpile rod size. The structures allowed for the observation of higher-order stop gaps.

Force-controllable, optically driven micromachines fabricated by single-step two-photon microstereolithography

We have fabricated optically driven micromechanisms and demonstrated their motion under optical force. All of the movable microcomponents are directly fabricated through an assembly-free process using the high-speed scanning of a femtosecond laser focused inside a photocurable resin. Since these movable micromachines are made from photocurable resin transparent to visible and near-infrared light, they can be driven by the force of optical trapping. We demonstrate a simple, versatile method for driving movable micromachines. Part of the movable component is optically trapped by a single laser beam and manipulated according to the desired trajectory. Various types of motion, including rotation and swinging are demonstrated. In addition, the optically driven micromachines can be force-controlled to femtonewton order by adjusting the position trapped by the laser beam. We demonstrated the femtonewton order force-controllable swing motion of micromanipulators. A microturbine was rotated by circular scanning of a trapping laser beam in a liquid. Such force-controllable optically driven micromachines are promising manipulation tools for biomolecules such as DNA and protein.

Recent Progress in Three-Dimensional Microstereolithography.

In recent years, microstereolithography techniques have been used to fabricate various types of three-dimensional micro/nano devices such as microelectromechanical systems, micro total analysis systems and photonic crystals. Two-photon microstereolithography is one of the most promising methods in microstereolithography. This paper describes the fabrication principle, a fabrication system and the latest experimental results of two-photon microstereolithography. In addition, several applications of two-photon microstereolithography, including optically driven micromachines and photonic crystals, are introduced. Two-photon microstereolithography is useful for not only micro/nano technologies but also biotechnologies.