Ultrasonic (Ultrasound) | Application

(Published 2026-07-30)

Ultrasonic Technology and Power Supply Solutions

Ultrasonic technology is utilized in various fields of modern society, from industrial product manufacturing to medical diagnosis. The performance of processes such as ultrasonic machining, cleaning, welding, non-destructive testing, and medical diagnosis largely depends on the performance of the power supplies and generators that drive the ultrasonic transducers. This page explains the basic knowledge of ultrasonic waves and the power supply technology required to maximize their performance.

What is Ultrasonic?

Ultrasound refers to sound waves with frequencies above the upper limit of human hearing, generally 20 kHz. Sound waves are mechanical vibrations that propagate through mediums such as air, liquids, and solids, and ultrasonic waves are a type of these waves. Generally, sound waves of 20 kHz or higher are called ultrasonic. Frequency bands from 20 kHz to several MHz are widely used in industrial applications, while frequencies from several MHz to tens of MHz are used in medical diagnostic applications. Ultrasound exhibits strong directionality and possess properties that cause them to reflect, absorb, or transmit when they hit an object. Utilizing these properties, various applications such as machining, cleaning, welding, measurement, inspection, and medical diagnosis are realized.

Principles of Ultrasound Generation

To generate ultrasonic waves, ultrasonic transducers incorporating piezoelectric elements are widely utilized.

Generation of Ultrasonic Waves by the reverse piezoelectric effect
When an alternating voltage is applied to a piezoelectric material such as PZT (lead zirconate titanate), the material expands and contracts according to the polarity of the voltage. This phenomenon is called the reverse piezoelectric effect. By applying a high-frequency AC voltage, the piezoelectric element vibrates at high speed, converting electrical energy into mechanical vibration energy to generate ultrasonic waves.
The Importance of Resonance
An ultrasonic transducer has an inherent resonant frequency determined by its shape and material. Driving the transducer near its resonant frequency allows for a large vibration amplitude with minimal input power, enabling highly efficient energy conversion. Therefore, it is crucial for many ultrasonic systems to operate while maintaining this resonance point.

Applications of Ultrasonic

1. Industrial Processing and Precision Machining (High-Power Applications)

Ultrasonic Machining

By superimposing ultrasonic vibrations on a cutting or machining tool, high-precision machining is achieved even for materials that have traditionally been difficult to process.

Machining of hard and brittle materials such as ceramics, glass, sapphire, and SiC wafers
High-precision machining of semiconductor materials and electronic components
Micro-drilling, cutting, and polishing

Ultrasonic-Assisted Cutting/Machining

By adding ultrasonic vibration to cutters or drills, the contact between the tool and the workpiece becomes intermittent, which achieves:

Reduction of frictional resistance
Mitigation of cutting load
Suppression of burrs
Improvement of machining accuracy

Ultrasonic Welding

This is a technology that joins plastic parts or films using high-frequency vibrations. It is widely used in the manufacturing processes of automobiles, electronic devices, and medical equipment.

Ultrasonic Cleaning

This process removes contaminants from component surfaces and inside microscopic structures by utilizing cavitation and acoustic streaming generated in a liquid.

Ultrasonic Atomization

This technology generates a fine mist by applying ultrasonic vibrations to a liquid. It is utilized in coating equipment, humidifiers, and medical devices.

2. Measurement and Inspection Applications

Non-Destructive Testing (NDT)

By propagating ultrasonic waves into the interior of a material and analyzing the reflected waves, internal defects, cracks, and delamination can be detected.

Distance Measurement and Position Detection

By measuring the propagation time of ultrasonic waves, the distance and position relative to the target object can be detected with high accuracy. This is widely adopted in:

Level meters
Distance sensors
Proximity sensors

Ultrasonic Flow Meters

Ultrasonic flow meters measure fluid flow without direct contact with the process fluid.

3. Medical Applications

Diagnostic Ultrasound Systems (Echography)

This equipment visualizes internal tissues and blood flow conditions by transmitting ultrasonic waves into the body and analyzing the reflected waves.

Therapeutic Ultrasound

This utilizes focused ultrasound or high-intensity ultrasound to perform tissue treatment and medical procedures.

Power Supplies for Ultrasonic Applications

Power Supply Requirements for Ultrasonic Systems

To drive ultrasonic transducers efficiently, dedicated power supplies called ultrasonic drivers (ultrasonic generators) or ultrasonic power supplies are required rather than general DC or AC power supplies. Depending on the application, technology is required to stably supply high-frequency voltages ranging from tens of volts to hundreds of volts, or even into the kilovolt range.

Functions and Characteristics Required for Power Supplies

1. Wide Frequency Range Operation

It is necessary to generate high-frequency AC voltages from 20 kHz to several MHz depending on the application, and to drive the ultrasonic transducer at the optimal frequency.

2. Impedance Matching

Since a piezoelectric transducer behaves as a capacitive load, impedance matching between the power supply and the transducer is critical. Without proper matching, problems such as the following will occur:

Decrease in power transmission efficiency
Increase in heat generation
Insufficient output This technology is particularly indispensable for high-power ultrasonic machining equipment and ultrasonic welding equipment.

3. Waveform Control and Stability

Optimal waveform generation is required according to the application.

For Non-Destructive Testing Applications:

High-voltage pulse driving
Short pulse generation
Fast rise time characteristics

For Medical Applications:

Low noise
High-stability frequency control
High-precision pulse control

4. Automatic Resonance Tracking

The resonant frequency of an ultrasonic transducer changes due to temperature variations and load fluctuations. Therefore, high-performance ultrasonic generators monitor the phase difference between voltage and current as well as impedance changes in real-time, automatically tracking to the optimal resonant frequency. This enables:

Improvement of vibration efficiency
Reduction of heat generation
Maintenance of stable output

The Importance of Power Supplies in Ultrasonic Systems

The performance of an ultrasonic system is heavily influenced not only by the ultrasonic transducer itself but also by the performance of the power supply and generator that drives it. Achieving highly efficient energy transfer, high-precision frequency control, and stable output supply leads to improvements in machining quality, inspection accuracy, and productivity. Matsusada Precision offers a wide range of high-voltage power supplies for driving ultrasonic transducers and piezoelectric devices, as well as power modules designed for integration into ultrasonic drivers and various control systems. We provide power supply solutions optimized for each customer's ultrasonic application, enabling stable, efficient, and reliable system operation.

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