I am sure it would sound like a crazy story, but the fact is that I got involved with ultrasound as a joke! As a young materials scientist with specialization in materials processing and characterization, I began my industrial carrier at PPG Industries, a major flat glass manufacturer in 1973. On my very first day at work, my manager asked me to find a method to test a very large block of a multi-layered porous refractory at 1,000 C. I proposed high frequency sound. He liked it and gave me lots of money to play with!
This was the first time I heard about real non-destructive testing and ultrasound, since my background was in characterizing materials with x-ray, electron and neutron beam and optical methods for structural and compositional analysis. At that time all ultrasonic techniques required a liquid between the transducer and the test material. But my test materials were porous ceramics. When I enquired dry coupling transducer, they all laughed at me! Nevertheless, I got very deeply involved with ultrasound like love at first sight! I saw possibilities after possibilities for nondestructively get more information about the materials, besides metals-type defect detection, perhaps the only use of ultrasound then. Ultrasound was a virgin field!
I quit my job and started Ultran in 1978 with the key objective of developing ultrasound analogous to other wave based materials analysis methods. This required total overhaul of ultrasound.
My first dream was to create a transducer with extremely short pulse (for high resolution) and extremely broadband (for spectroscopy) transducer. Known as UNIPOLAR LAMBDA transducer, we made it in 1979. We were dumbfounded to see half cycle in time domain and near flat spectra in frequency domain. Several people started the rumor that I had “doctored” the pictures showing the acoustics of LAMDA transducers! When a researcher used it to test aluminum, I was told they couldn’t use it, because it showed much too much and that their customers would reject all materials!
Next came the high temperature transducers followed by dry coupling and air/gas coupling transducers in 1983. They found limited use in testing porous, fragile, and liquid sensitive materials. Meanwhile we developed a comprehensive scheme for total characterization of materials, particularly for ceramics and powder metals – all the way from green stage to fully sintered stage.
These developments earned Ultran very good reputation in the industry and educational institutions. But I was not satisfied! Although our 1983 air/gas propagation transducer were OK for testing a handful of materials type, I envisioned further improvement for non-contact ultrasound testing of all materials. Some of my associates openly said, “I was crazy and belonged in an institution!” This only encouraged me and made challenge more exciting!
By hit-and-trial and by empiricism in 1999 I conceived a design that literally shook me when I observed massive ultrasound signals in air even at MHz frequencies. So high was the air/gas transduction of these transducers that we could transmit quality signals through thick sections of steel without any contact! On that day I had to take two-hour walk outside my lab to make sure that I wasn’t hallucinating! To confirm, I asked my colleague if he too was observing what I was. On that day not just Ultran, but entire ultrasound and materials world changed. Obviously, the Z barrier between air/gas and materials had been overcome and Non-Contact Ultrasound (NCU) became a living reality.
NCU transducers are now produced from 30 kHz to 5.0 MHz (US and International Patents) and in most cases their performance rivals conventional ultrasound. Out of necessity in 2001, we also developed a new piezoelectric composite. Known as Gas Matrix Piezoelectric (GMP) composite, it is characterized by extremely high efficiency, coupling factors, bandwidth, and sensitivity (US and International Patents.) GMP is produced from 30 kHz to 500 kHz, thus bridging the age-old gap for very low frequency ultrasound. Along with this we have also developed a number of novel NCU materials evaluation techniques.
We undertook the responsibility of overhauling ultrasound as well as to develop its methodology matching other materials testing and characterization methods. We are proud to deliver this with our novel ultrasonic systems, laboratory analytical facility, training and education into modern ultrasound. All of this for the benefit of our socio-technical world – cost-effective materials production, process and quality control, savings of expenses, time and environment.
On paper Ultran looks like an old company, but in spirit it is as fresh as spring air! The excitement continues.
Founder, Chief Science Officer
The Ultran Group