Harnessing the Energy of Vibrations

A team of researchers at the Cambridge Center for Smart Infrastructure is preparing to field test an innovative vibration energy harvester to power sensors used to monitor factors affecting bridge safety.

The use of sensors to monitor both environmental and physical conditions affecting the safety of a bridge is one of the ways to mitigate the hazards of aging infrastructure. Even though these sensors are wireless, they current depend on battery packs that need to replaced on a regular basis. In the October issue of 
Civil Engineering, Catherine A. Cardno, Ph.D. describes research underway at The Cambridge Center for Smart Infrastructure at Cambridge University in the United Kingdom to develop a next generation vibration energy harvester that, if successful, will eliminate the need for manual replacement of bridge sensors.

The Technology
These energy harvesters transforms the vibrations induced by the traffic crossing the bridge into energy. Unlike the current vibration harvester available, this new technology relies upon parametric resonance to amplify the bridge vibrations. With the amplification, these new harvesters can provide a steady source of energy even though the actual vibrations caused by the traffic crossing the bridge are unpredictable and variable. In addition, these harvesters, which range in size from the dimensions of two 4.5 volt batteries to those of a 9 volt battery, are able to collect a greater spectrum of vibration than the current harvesters available.

The research team plans to field test this new technology on a 2.5 km suspension bridge in Edinburgh, Scotland in Spring 2016.