Battery-free sensing

Instrumentel, a spin-out from the University of Leeds, has developed a communications system which can act as both a sensor and an actuator, without requiring batteries. The system, which uses inductively coupled wireless telemetry, can be used to transmit and receive information in tight spaces and harsh environments.

The technology has two main components. A miniature transponder, in the form of an electronic tag, is connected to the sensors and actuators mounted on the equipment being controlled. The inductive power is provided by a reader, a compact device that also communicates the tag.

‘Normally, inductive coupling has a very short range - only 20mm or so,’ says Instrumentel’s chief executive, Steve Couchman. ‘We’ve managed to go to ten times that.’ The reader also transfers a clock signal to the tag, which means that it can work at high temperatures, Couchman says.

One of the company’s key products, IntraSense, was originally invented for Formula 1 engine development. However, Couchman says, it has a wide range of process applications, such as pH level sensing. ‘We incorporate the pH sensor and temperature sensor into a magnetic stirrer, so we can improve the productivity of pH-sensitive reactions - there’s no need to insert probes into vessels,’ he says.

The next stage is to incorporate all the electronics for the tag onto a silicon chip, Couchman says. Not only would that make the tag more compact, it would also require less power to run, which would boost the range further.