Deputy Head of School (Enterprise)

Professor Neil White’s work on smart, self-powered sensors has been of interest to the media in recent years, particularly this year, when the media announced that the prototype of the Southampton Remedi-Hand, a new light-weight prosthetic limb containing many novels sensors, is ready to be built.

From as far back as he can remember Professor White has always enjoyed maths and physics, so it is hardly surprising that he was attracted to electronics. He studied a degree in Electronic Engineering during which time he came into contact with sensors for weighing materials such as wool, coal, wheat and various powders during his industrial placement period at a small process engineering company in the Midlands.

He came to the University of Southampton in 1985, where he decided to develop his knowledge of sensors further and studied for a PhD in thick film piezoresistive (strain gauge) sensors. After completing his PhD in 1988, he worked as a research fellow at University of Southampton Institute of Transducer Technology (USITT) where he developed a number of different transducers, including one of the first types of thick-film pressure sensor for automotive applications.

His career has led him to go on to become a Lecturer at the University of Southampton in 1990, a Senior Lecturer in 1999, a Reader in 2000 and he is currently Professor of Intelligent Sensor Systems with the University’s School of Electronics & Computer Science (ECS).

Over the years, Professor White became increasingly interested in new materials for sensor applications and in 1991, he developed a thick film piezoelectric material which made it possible to produce a sensor which could power itself if it were installed in a device that vibrates and would be ideal for appliances where physical connections to the outside world were difficult.

Professor White commented: ‘We began to understand how the material worked and found that it would work best if you have a sensor buried in a device that you cannot easily access. The ideal scenario is to have a device that will generate power from a vibration source which will in turn power the sensor.’

The Southampton Remedi-Hand proved to be the ideal home for these sensors and Professor White and his colleague, Dr Paul Chappell have already designed this ‘clever’ prosthetic hand which can mimic movement and they are about to start building a fully functioning prototype. It will have piezoelectric sensors in each of the five fingertips which will detect how much force is being exerted on the tip and translate this information into an electrical signal which will be fed to a small processor.

Professor White said: ‘The aim is to create a hand with the sort of functionality a human hand has but also a sense of touch. This will let the hand know how tightly to grip an object like a coffee cup without dropping it, but not so tightly that it’s crushed. It’ll also have an integrated slip-sensor which will tell the hand if something is beginning to slip out of its grip so it can grip slightly harder.’

Further research into alternative energy sources based on electromagnetic techniques and a desire to find applications for them led to the creation of Perpetuum, a University spin-out company, of which Professor White is a founder member.

He commented: ‘We set up Perpetuum to exploit the work we had done in energy harvesting.’ Perpetuum researchers have developed small, inexpensive wireless sensor systems with RF data transmission. The patented vibration harvesting microgenerator produces sufficient energy from relatively low levels of vibration to power the systems so they require no external power supplies or batteries.’

Among many potential applications, these could be used to monitor stress and find dangerous fractures by being embedded in structures such as bridges and aircraft, or monitor the health of rotating parts and moving vehicles. Future planned developments could lead to an everlasting heart pacemaker. Sensors in use at present are limited by the need for a power supply or batteries, but Perpetuum's version will capture its own energy from the environment. For example, a sensor on a railway track could reduce rail accidents by using vibration energy harvested from passing trains to report faults in the track or rolling stock over the mobile phone network. Work is underway to miniaturise the device to the size of a 5p coin.

Professor White commented: ‘The vibration power concept is certainly relevant to people today, for example, self-powered watches have taken off because they can be powered by movement. Some of our Perpetuum devices are still relatively large and the challenge is to shrink them and yet still maintain the power.’

Professor White is satisfied with his achievements and plans to keep up the momentum with the development of sensors. Even the recent fire in the building, which housed most of his research, has not dampened his enthusiasm. He commented: ‘One of the things that impressed me was that despite this devastation, there has been a tremendous desire to forge ahead and our researchers have picked up their work again really quickly and are getting on with it.’

He is also very interested in making sensor arrays where multiple sensors work together in applications and is looking at combining thick film materials with silicon, so that more cost-effective sensing technologies can be developed. He explained: ‘We can take a basic silicon structure and add to it and develop a template which can be built on to produce lower cost, mass reproducibility and reliability which could have a major impact on the electronics industry.’