Technical news

Now and Then: Our past is often a guide to our future

For over 50 years Murata has combined the ability to identify opportunities with the corporate discipline needed to exploit those opportunities. Here we take a look back at the company's first 50 years of success in the field of sensor technology, and a view on what the next 50 may hold.

Founded at the very beginning of the electronics revolution, Murata and its board has enjoyed over half a century in one of the most significant and rapidly changing industries in the world. That brings with it not only a wealth of experience but also an insight in to the direction in which the complex world of electronics is travelling.

Increasingly, our ability to interface to the environment around us is playing a crucial role in that direction.

Sensors and the Environment

Today we enjoy a much greater level of mobility and freedom, under far safer conditions, than at any other time in the history of modern man. Enabling that freedom of mobility is the integration of advanced electronics with the natural world.

Sensors provide the crucial interface between electronics and the environment. Through developments in sensor technology, we are able to detect motion, temperature, humidity, light and many more physical phenomena, and use that information to improve the lifestyle and living conditions of countless people. The accuracy, reliability and stability of sensor technology is key to its success and over the years Murata has developed technologies which provide these crucial elements, with increasing scope. One of the earliest yet, still, fundamental physical materials to be employed in sensor development were ceramics. These materials possesses key attributes, which make their use both wideranging and versatile.

Ceramics can be configured to exhibit the natural electromechanical phenomenon, piezoelectricity. This is where mechanical stress can be used to generate electrical energy and as such piezoelectric ceramics present a vast opportunity for sensor development. The very first sensor developed by Murata was a water, which allowed this first sensor to be used as an ultrasound transducer (receiver and transmitter) to locate shoals of fish in the open ocean.

Birth of piezoelectric ceramic modules

Piezoelectric ceramic can be applied in various sensor applications and for a long time this was Murata's focus, specifically in exploiting the physical properties of piezoelectric ceramic to make sensors for detecting various physical stimuli. But there was also a period where it was taken to the next level, creating modules using those sensors to achieve greater functionality.

However, after about a decade of activity in this niche sector, it became clear that the end customers' requirements were best served at the sensor level, instead of repeatedly developing bespoke modules. As a result a strategic decision was made to return to the company's area of expertise and revisit the markets for piezoelectric sensors.

At about the same time, around the end of the 1980s and beginning of the 1990s, there was a shift emerging in the industry. The scale of integration now meant there was much more opportunity for sensors in more diverse applications. The laptop computer is a good example.

Designed to be portable, it suffered from an obvious weakness; hard disk drives are prone to data loss caused by sudden movement or shock. In a desktop environment this isn't a major problem, but for a portable computer it becomes a serious issue.

Following investigations in the use of piezoelectric ceramics as acceleration sensors, Murata secured a leading position in this emerging market. Thanks to the innovative solution developed by Murata, manufacturers were able to detect the shocks that could damage a sensitive disk drive.

This enabled laptop manufacturers to include technology that could physically disengage the reading mechanism in a disk drive before damage could occur, thereby protecting the disk drive and its contents. Murata has seen massive success in developing and delivering sensors for hard disk drives in laptop and notebook PCs, as a result of its foresight and willingness to explore a new application area.

Detecting temperature changes

The increased integration in the industry demanded a new generation of sensor, one that fundamentally provided the same functionality but with more sophistication. It also provided new opportunities for existing solutions, such as Murata's POSISTOR technology. First developed in the late 50s, POSISTOR became the industry's first ceramic based positive temperature coefficient thermistor. This technology was first used to control the input power in high voltage equipment, such as heaters, degaussing circuits for TVs, and motor start circuits.

However with the use of integrated circuits increasing, it became clear it was equally applicable to detecting temperature changes (its primary application area) in low voltage circuits.

To fully exploit this opportunity, Murata applied its semiconductor ceramic materials and sintering process technology to develop a multilayer chip POSISTOR , which was commercialised in 2003. This project was so difficult, the engineering team originally said it couldn't be done!

These examples show how an intimate understanding of an established technology, like piezoelectric ceramics, has allowed Murata to identify new markets and develop new solutions for those markets, over a period of decades. Also key to this success is identifying where the technology can be applied, often before the market has realised it needs it.

Image stabilisation with gyro sensors

A prime example here is the company's success in image stabilisation, now used extensively in digital still and video cameras and based on a gyroscopic sensor. Initially the use of a gyro sensor for optical image stabilisation was dismissed as unnecessary. It was felt that digital signal processors, already used in these applications, were capable of providing the same functionality electronically.

As consumer demand for higher resolutions and greater zoom quality developed, however, so too did the need for optical image stabilisation through the use of gyro sensors.

As the market for more sophisticated sensors has evolved, so has the need for the sensor technology to take a giant leap forward. The risk of not driving innovation is a lesson Murata has already learnt and so it remains dedicated to new solutions.

MEMS technology

The company's long route to commercialising MEMS technology is an obvious indication of this. MEMS stands for Micro Electro- Mechanical Systems and combines the mechanical world with semiconductor integration technology.

As such it has the potential to produce an entirely new array of sensor solutions, for applications that have yet to be conceived. But it also represents a significant design challenge.

Murata started work on MEMS technology in the early ‘90s, long before it was commercially viable. However despite numerous hurdles and setbacks, Murata is now introducing acceleration sensors built using MEMS technology that are far superior in terms of stability over ceramic based sensors. In the future, these sensors will be viable solutions for a range of low frequency movement detection, such as making prosthetic limbs more responsive.

More opportunities for this technology will emerge as applications are discovered and thanks to its unique nature, those applications could fall outside Murata's existing business spectrum. For instance, MEMS technology could be applied in the chemical industry, enabling the cost of diagnostic equipment to fall to a level everyone can afford. Imagine the effect on world health that could have!

While it may not be clear where the demand or opportunities will come from, one thing is certain, however, Murata will be there to sieze them.

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