KERI Dr. Kim In-seong's team identifies deterioration and failure.
Development of elastic wave electrical sensor technology with built-in preamplifier
Eco-friendly sensor using lead-free materials to replace lead


The impact of natural disasters due to rapid climate change is raising concerns about the durability and safety of large-scale external buildings and structures. In particular, with the implementation of Korea's Green New Deal policy, a large number of electrical and energy facilities are being built, increasing demand for technologies that can predict and diagnose on-site accident risks.

On the 10th, Dr. In-Seong Kim's team at the Korea Electrotechnology Research Institute (KERI)'s Electrical Conversion Materials Research Center developed a 'preamplifier-embedded electrical sensor technology' that can diagnose signs of deterioration or failure in various facilities and equipment in advance by detecting acoustic emissions, which are microscopic vibrations transmitted from elastic bodies.

Elastic waves are a type of wave generated when a material is deformed or broken. The greater the degree of destruction or abnormality in the material, the more elastic waves are generated. The technology developed this time is a system sensor that can prevent major accidents in advance by monitoring signs of equipment deterioration or failure in advance through detection of elastic waves generated naturally from the equipment itself.

The research team built a preamplifier that amplifies small elastic waves at their source, thereby reducing the noise level that interferes with measurements to the same level as the US company PAC's product, at 25dB. Using KERI's own piezoelectric technology, the team succeeded in localizing the 'preamplifier-built elastic wave electrical sensor (AE Sensor)', which has a measurement sensitivity of 85-90dB, which is higher than that of existing products (80dB).

A new lead-free material has also been developed and implemented to replace the lead used in existing sensor materials. With the Restriction of Hazardous Substances (RoHS) directive banning the use of lead in electrical and electronic devices starting in July next year, this new material is expected to replace existing products.

This sensor technology is expected to be primarily utilized in the safety diagnosis field of the energy industry, including ▲diagnosis of various facilities and components of nuclear, thermal, wind, and hydroelectric power plants, ▲abnormal diagnosis of transformers and circuit breakers in large substations and power plants, and ▲preliminary detection of structural deterioration and deformation of oil tanks and large oil tankers.

In the case of wind power, it is expected that stable facility operation will be possible by being able to measure damage to the generator's shaft, bearings, gears, oil contamination, etc. in advance. Hydroelectric power plants can also monitor and take proactive measures to prevent potential failures in valves, steam lines, and joint pipelines.

In addition, it can be used to prevent accidents in large buildings and facilities, such as ▲diagnosing abnormalities in the main towers and ropes of large suspension bridges, ▲observing bending and destruction of concrete and civil engineering structures, and ▲detecting seismic waves (P waves, S waves) transmitted within the earth's crust.

Dr. Kim In-seong said, “The sensor we developed this time can be applied to various fields such as strengthening the competitiveness of the national safety diagnosis sector and autonomous vehicles, smart factories, and healthcare,” and “It is still at the sensor stage that detects elastic waves in a designated resonant frequency band, but in the future, we plan to expand the bandwidth and develop a composite sensor that includes wideband and acceleration.”

In the future, the research team plans to improve the perfection of the technology, promote mass production of sensor elements in conjunction with the Gyeongnam Changwon Gangso Research and Development Special Zone project, and discover demand companies to promote commercialization.