Western Mail Profiles: Dr Lijie Li, Swansea University

‘Looking for a greener alternative to chemical batteries through the use of sensors and actuators’

Dr Lijie Li is a senior lecturer in the College of Engineering at Swansea University.

Sensors and actuators are devices used everywhere – in phones, computers, electronic household appliances, and all kinds of modes of transportation.

Each of the above contain many sensors or actuators to convert environmental parameters such as light or temperature into electronic signals, and vice versa.

Therefore, the global market for sensors and actuators is amazingly huge.

My research at the College of Engineering, Swansea University, is set to deliver novel research in the broad area of sensors and actuators.

I’m currently focusing on three main research themes – integrating interface circuits with micro sensors and actuators, producing green batteries for low power consumption devices, and researching nanomaterials and devices.

Every single sensor needs an interfacing circuit for processing the output data to a display panel.

Some sensors may have very small outputs, some may have large outputs.

Therefore, special interface circuits need to be designed for each type of sensor.

Similarly, for the actuators – devices which convert electrical energy into mechanical movement – special circuits have to be designed to satisfy the requirements of individual types of actuators.

In order to minimise the whole system to make it portable and compact, an integrated solution should be followed.

Integrating sensors and actuators with interfacing circuits is an ongoing challenge, and one that our team here at Swansea is keen to address.

Chemical batteries, which are widely used in everybody’s lives, destroy environments by emitting poisonous substances, and they either need to be frequently charged or abandoned when the power is gone.

Researchers have been thinking of ways to produce batteries without using chemical materials. There are many emerging alternative battery technologies, such as solar cells and mechanical batteries.

We’re interested in researching mechanical batteries, which work by harvesting mechanical movements and turning them into electrical energies.

Mechanical batteries can continue working for a very long time, and are environmentally friendly.

Nanomaterials are ones with morphological features on the nanoscale.

This is usually defined as being smaller than a one tenth of a micrometer in at least one dimension. There has been extensive research interest worldwide into nanomaterials and devices due to their superior electrical and mechanical properties.

For example, zinc oxide is a type of nanomaterial that can be operated in very high temperatures and can resist very high electrical voltage.

Graphane, a newly discovered material, has many potential properties yet to be discovered.

We are trying to investigate potential properties of these new materials and to integrate them with existing micro devices in order for them to be better used.

To contact Lijie email L.Li@swansea. ac.uk.

This article first  appeared in the Western Mail‘s Health Wales supplement on the 27th February 2012, as part of the Welsh Crucible series of research profiles.