Wireless, Battery-less Sensor Systems
Transense develops and markets patent-protected sensor systems for measuring torque, temperature and pressure, wirelessly and without the need for batteries, using Surface Acoustic Wave (SAW) technology.
As no batteries or wires are required, the sensors can be used in applications that traditional sensors cannot, such as on rotating shafts or in environments where access to the sensors is difficult or potentially hazardous.
Transense is developing the technology in conjunction with partners including McLaren Electronic Systems and General Motors, as well as via two wholly owned divisions, IntelliSAW and Translogik, targeting the high growth global electrical Smart Grid applications market and the transport industry respectively.
The Benefits of SAW Technology
SAW devices, as deployed by Transense, are realised as crystalline quartz substrates (dies) typically 6 x 4 mm by 350 microns thick. On each die up to 3 resonators, with natural frequencies around 433MHz, are laid down in thin film aluminium, using photo-lithographic techniques. Each resonator comprises a central inter-digitated transducer (IDT) with a series of reflecting strips distributed on either side. Overall resonator dimensions are 2 to 3 mm long x 0.3 to 0.4 mm wide. The spacing between individual features in the IDT and reflectors is of the order of 2 microns so you need a microscope to resolve the fine detail. SAW resonators respond to both mechanical and thermal strain by changing their natural frequency of vibration..