OREANDA-NEWS. Hitachi, Ltd. and Hitachi Automotive Systems, Ltd. today announced that they have developed a semiconductor strain sensor that combines a sensor element and control circuit in a single chip, along with an original bonding technology, and have begun full-scale volume production of the new strain sensor.

The strain sensor can be installed in automotive devices, industrial devices, various infrastructure buildings and facilities, to accurately measure physical changes in strain resulting from forces exerted on those devices and structures. In this way, it will be possible to efficiently manage and control status of those, for example to enable the smooth operation of devices, and to diagnose the signs of potential failures. Furthermore, an original metal bonding technology incorporated into the strain sensor minimizes deterioration in the junction segments, achieving outstanding reliability in the long term.

The Hitachi Group will produce these strain sensors using the volume production platforms and high durability technologies that it has cultivated through the development of automotive components. At the same time, by utilizing these technology platforms in the future, it will roll out the strain sensors in a broad range of fields, including automotive, power systems, and industrial devices, aiming to create applications in solution services targeting the "Internet of Things" (IoT).

In recent years, new trends have arisen in the field of IT, as exemplified by M2M (Machine to Machine) technologies and the IoT. As more and more things become connected via networks, data that had not been used in the past is now creating new value. In the Social Infrastructure field, which includes automotive devices, industrial devices, and various infrastructure buildings and facilities, using sensors to measure and analyze physical changes in strain volumes is an effective way of ensuring that those devices, equipment, and various infrastructure buildings and facilities can be used with stability over many years.

In many social infrastructure fields, however, sensors must operate for long periods of time in harsh environments characterized by high temperatures and high humidity. This places a huge burden on the sensors, and it becomes difficult to use conventional strain gauges, which are currently the mainstream, for extended periods of time, because the organic materials in the junction segments tend to deteriorate. In addition, depending on the type of object being measured, as in the case of motors, sensors are affected by electromagnetic noise, making it difficult to measure the data accurately. This has given rise to a demand for high functioning, high reliability, long-lasting sensors that can be used in a broad range of applications.

Hitachi Automotive Systems has now begun volume production of a strain sensor that uses an original heat-resistant, low-creep metal junction technology, enabling highly accurate measurements over long periods of time in heat environments with temperatures ranging from -40? to +120?. Using a common sensor element, the sensor can measure changes in a wide range of physical quantities such as weight, pressure, torque, tension, and shear force, and can also continuously measure gradual changes, for example in low frequency vibrations.

As such, it can be used in a wide range of fields, such as fluid volume measurement or the leveling of precision devices. The strain sensor incorporates CMOS processes, so it is compact and energy efficient, and by adopting a miniaturized sensor element, the effects of electromagnetic noise have been minimized as well. For this reason, it can be used not only in large infrastructure buildings and facilities, but also in small medical devices, where sensor installation had been difficult in the past.

To give one example of an application for strain sensors, Hitachi Automotive Systems has been shipping torque sensors since the end of 2012 as a mechanical component in battery assisted bicycles. The sensor measures the torque generated in the shaft when the rider pedals, enabling optimum motor drive to ensure smooth control in the pedal assist function.

Recently, the Hitachi Group has begun research targeting the application of strain sensors in collaboration with industry and academia in the machinery, medical, construction, and civil engineering fields. Sensor technologies are expected to become a core technology contributing to increased competitiveness in Japanese industry. In the future, the Hitachi Group will roll out strain sensors not only in automotive applications, but also in Hitachi's own power systems, construction machinery, industrial devices, medical devices, and infrastructure facilities. By connecting these and other devices via networks, Hitachi will strive to create applications in solution services to meet new needs in the era of the IoT.