JPS6046458A - Ultrasonic microscope - Google Patents

Abstract

PURPOSE:To enable observation of a material of which the sample reacts, swells or dissolves with a medium by coating the sample surface with an org. high polymer film deposited by evaporation so that the medium does not contact directly the material to be observed. CONSTITUTION:An org. high polymer film (polyparaxylene) deposited by evaporation is a thermoplastic resin and can form a film on a sample surface when deposited by vacuum evaporation. Said film can be formed as thin as 0.2mu and the thickness thereof is freely controllable. The film can be deposited uniformly by evaporation into any concealed part without generating pinholes as far as there is a space therein. The easy observation of a material which is easily dissolved or a material which is easily swollen is made possible as the direct contact of the medium with the sample is prevented by sticking such polymer film to the sample surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an acoustic lens that is suitable for use in a microscope that utilizes high frequency sound wave energy.

[Background of the invention]

In recent years, as it has become possible to generate and detect high frequencies up to IGHz, the wavelength of sound waves in water is about 1 micron, and therefore, microscopes that utilize sound wave energy have been considered.

The configuration of such an ultrasonic microscope is shown in FIG.

A high voltage pulse 2 generated from a pulse oscillator 1 is applied to a piezoelectric material 4 formed on the upper surface of a spherical lens 3 by vapor deposition or the like. This piezoelectric material 4 is excited by the high voltage pulse 2 and generates ultrasonic waves. This ultrasonic wave propagates through the spherical lens 3 and is narrowly focused by a concave portion provided on the other end surface.

This ultrasonic beam is irradiated via the medium 5 onto the surface of a sample 6 (placed on a sample stage 10) which is being mechanically scanned in two dimensions. The sound waves reflected from the sample 6 are received by the same spherical lens 3, converted into electrical signals by the receiver 7, and can be displayed on the screen of the CRT 8 in synchronization with the scanning of the scanning device 9 of the sample stage 10. .

When using this type of ultrasound microscope, sound waves propagate even in optically opaque objects, allowing us to understand their internal structures. Moreover, it is attracting attention as a new observation device because it can depict the fine structure of an object that reflects its physical properties such as elasticity, density, and viscosity, allowing it to obtain information that is not possible with other microscopes.

When observing a sample using the ultrasonic microscope configured as described above, observation may be difficult if the sample is a substance that reacts, swells, or dissolves in the medium 5 (for example, water). It's impossible.

[Purpose of the invention]

In view of this, an object of the present invention is to provide an ultrasonic microscope in which a medium does not come into direct contact with an observation substance.

[Summary of the invention]

In order to achieve this object, the present invention is characterized in that the sample surface is coated with a vapor-deposited organic polymer film.

[Embodiments of the invention]

The second south shows the sample 6 attached to the upper surface of the sample stage IO. By applying the coating material 11 on the surface of the sample 6, the above-mentioned problem can be solved. It has been found that, for example, a vapor-deposited organic polymer film is suitable for the coating material 11 used here. This evaporated organic polymer film (polyparaquinrylene) is a thermoplastic resin that can be formed on the surface of a sample by vacuum evaporation. can be controlled. Also, as long as there is space in any hidden place, it can be deposited uniformly and without pinholes.

Furthermore, since the temperature during vapor deposition is room temperature or lower, no thermal hindrance is caused to the sample.

By attaching a polymer film with these features to the surface of a sample, it is possible to easily observe substances that are easily dissolved or swelled in order to prevent the sample from coming into direct contact with the medium.

Furthermore, in general, at the interface between two materials where the acoustic impedance is large at Zl and z2, waves only partially pass through C.
・. The rest goes towards the sound source (21-22)/(Z□+Z2)
At the solid-liquid interface, the acoustic impedance Z1 of the solid is ~10 x 10' g
/am" 6 sec or more, the acoustic impedance z2 of the liquid is ~1.5 X I O'g/am"・se
・Almost 10 times larger than C. In this case, since the above ratio approaches 1, most of the sound waves are reflected, and only a small portion of them are transmitted.

This phenomenon can be eliminated by creating a special layer at the interface. The material forming this layer must be selected to have an acoustic impedance between 21 and 22, and the acoustic impedance z3 of the above-mentioned polymeric material is 3 X l O'g/Cm"
a sea, which is approximately halfway between the two, so by depositing this material to a thickness equal to λ/4, it can serve as a matching layer.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the schematic configuration of an ultrasound microscope, 42
LQ is a diagram illustrating a main part of an embodiment of the present invention. 6: sample, lO: sample stage, l: vapor deposited organic polymer film Rin l @

Claims (1)

[Claims] 1. A sonic microscope that detects sound wave energy disturbed by an object placed near the focal point; An ultrasonic microscope characterized by having a vapor-deposited organic polymer film.