Yasuhiro Mizutani

Three-dimensional shape measurement using focus method by using liquid crystal grating and liquid varifocus lens

This paper describes a surface profile measurement using a varifocus lens by an optical sectioning. The focus method is utilized for a uni-axis optical system of projection and observation. The varifocus lens is mounted on between a liquid crystal grating and a projection lens. A focus length can be continuously varied from a concave to a convex shape by changing the liquid pressure. The contrast of projected pattern onto the sample is approximated the Gauss distribution along the distance and indicates sharpest at the focused plane. It is possible to analyze the contrast distribution by a grating projected method using a liquid crystal grating with 4 steps phase-shifting method. The liquid crystal grating is powerful tool to make arbitrary intensity and frequency distribution. Surface profiles of mechanical parts have been measured to demonstrate for this method.

Three-dimensional profilometry based on focus method by projecting LC grating pattern

This paper describes a 3D surface profile measurement based on focus method by an optical sectioning. The optical system is employed uniaxial condition of projection and observation axis. The contrast of projected sinusoidal pattern onto the sample is approximated the Gauss distribution along the distance. The highest contrast indicates at the focused plane. It is possible to analyze the contrast distribution by a grating projected method using a liquid crystal grating. A phase-shifting method is applied to the contrast analysis. The liquid crystal grating is powerful tool to make arbitrary intensity and frequency distribution. Surface profiles of mechanical parts were measured to demonstrate for this method.

Light-driven micromanipulator and its application for 3D fabrications

An optical actuator has some interesting characteristics, such as no generation of magnetic noise and receiving the energy remotely. A novel micromanipulator by photothermal effect is proposed. It consists of three optical fiber cantilevers. One end of the fiber is cut for a bevel and painted with black color. A photothermal effect is occurred responding to the incident beam at the end of the optical fiber. It can manipulate a sample and move it in the arbitrary place in 3D space. We succeed to fabricate the 3D structures.

Surface profile detection with nanostructures using a Mueller matrix polarimeter

Recently, the surface profiles of nanostructures have been reduced in size in order to develop microfabrication techniques, such as lithography and nanoimprinting. In particular, feature sizes of a few tens of nanometers are common in the semiconductor industry. This study uses a Mueller matrix polarimeter, which is based on a scatterometry technique, to evaluate the surface profiles of nanostructures. In this technique, a nanostructure profile is determined from the Mueller matrix which expresses all the polarization properties of the sample by experimental measurements and calculated values using rigorous coupled-wave analysis (RCWA). This technique is more useful than conventional scatterometry based on ellipsometry since it is able to determine the total polarization properties of a sample. This is because, the Mueller matrix is able to estimate the surface profile of a nanostructure to greater precision. The grating period of a Cr/Cr2O3 structure on a SiO2 substrate was measured using a dual-rotating retarder polarimeter. The experimental results agree well with the values obtained by numerical analysis. We measured the characteristic of non-diagonal elements in the Mueller matrix by varying the incidence azimuth of the sample. We have demonstrated the possibility of evaluating a nanostructure profile from the Mueller matrix.

Paul trapping for micro-particles and its application for crystal growth

Recently, crystal growth in the microgravity is attracting attention because it has possibility to produce uniform crystal. The purpose of our study is to manipulate a particle with micrometer of diameter and to produce crystal coincidentally by Paul trapping. Cylindrical electrodes were prepared for Paul trapping and electrospray ionization was brought in to charge particles. A micro particle of solid, liquid and solution have simple harmonic motion behavior. An electrical charge of trapped particles is derived from analyzing a motion of vibration particles using high-speed camera. After liquid particle is trapped, then it starts to be vaporized. To control position of the particle, it is applied voltage. Finally it is succeed to produce the crystal.

Micromanipulators Comprising Optical Fiber Cantilevers

We propose an optically driven micromanipulator which operates on the basis of the photothermal effect and possesses some interesting characteristics, such as non-generation of magnetic noise and the ability of receiving energy remotely. The manipulator is composed of three optical fiber cantilevers which are cut in a bevel shape and painted with a photo-absorbent material attached on the angled edge of the fiber. The photothermal effect is used for moving the manipulator when the incident beam is introduced at the end of the optical fiber. The manipulator can manipulate samples and move them to arbitrary places in three-dimensional space.

Optically controlled bimorph cantilever by Poly(vinylidene difluoride) and its application of optical actuator

An optically driven actuator is a non-contact method for the remote application of light energy. A new method for optically driving actuators which uses a polyvinylidine difluoride (PVDF) cantilever is proposed. The PVDF cantilever is coated with silver on one surface. The PVDF is a ferroelectric polymer that has both pyroelectric and piezoelectric properties. When one side of the cantilever is irradiated by a laser beam, an electric field is produced along cross-section of the cantilever and mechanical displacement occurs by the piezoelectric effect. The response of the PVDF cantilever is analyzed mathematically.

Three-dimensional optical control of magnetic levitation by temperature sensitive ferrite

An optical driven actuator has a feature of a non-contact for applying light energy remotely. It consists of a neodymium magnet as a movement, a ferrite magnet, two blocks of graphite and temperature sensitive ferrite. The neodymium magnet is levitated by magnetic force between the neodymium and ferrite magnet. When laser is irradiated on temperature sensitive ferrite, a magnetic force decreases by photo-thermal effect. As a result, the movement can be controlled in three-dimensional area.

Optical driving of actuator using Poly-Vinylidine DiFluoride cantilever

Optically driven actuators are a non-contact method for the remote application of light energy. We propose a new method for optically driving actuators which uses three polyvinylidine difluoride (PVDF) cantilevers as the legs and a polymer film as the body. The PVDF cantilevers are coated with silver on one surface. PVDF is a ferroelectric polymer that has both pyroelectric and piezoelectric properties. When one side of the cantilever is irradiated by a laser beam, an electric field is produced along cross-section of the cantilever and mechanical displacement occurs by the piezoelectric effect. We measured the response time and the generated force of the cantilever. Optically driven actuator move via the slip-stick effect.

Two-dimensional magnetic force actuator using temperature sensitive ferrite driven by light beam

A two-dimensional actuator has a feature of a non-contact for applying light energy remotely. It consists of a magnet as a movement, an acrylic plate and the temperature sensitive ferrite mounted on two-dimensional array on the plate. A curie temperature of the ferrite is set about room temperature. For moving the magnet, two ferrites in the opposite direction are irradiated by the laser. The magnetic force decreases by photo-thermal effect. For generating more strong force, a thickness of the plate and ferrite are optimized by analyzing static magnetic field. As a result, the movement is controlled in the two-dimensional area. Moreover, we attempt to control magnetic levitation.