Scientists develop super sensitive magnetic sensor

Researchers have developed a new hybrid magnetic sensor that is over 200 times sensitive than commercially available sensors.

This technological breakthrough hails opportunities for the development of smaller and cheaper sensors for various fields such as consumer electronics, information and communication technology, biotechnology and automotive.

The new sensor could fill performance gaps of existing sensors, and find applications as "thermal switches, hard drives and magnetic field sensors. Our technology can even be applied to flexible applications", said lead researcher professor Yang Hyunsoo from the National University of Singapore (NUS).

When an external magnetic field is applied to certain materials, a change in electrical resistance, also known as magnetoresistance, occurs as the electrons are deflected.

The discovery of magnetoresistance paved the way for magnetic field sensors used in hard disk drives and other devices, revolutionising how data is stored and read.

In the search for an ideal magnetoresistance sensor, researchers have prized the properties of high sensitivity to low and high magnetic fields, tunability, and very small resistance variations due to temperature.

The new hybrid sensor may finally meet these requirements.

The new sensor, made of graphene and boron nitride, comprises a few layers of carrier-moving channels, each of which can be controlled by the magnetic field.

The researchers characterised the new sensor by testing it at various temperatures, angles of magnetic field, and with a different pairing material.

Compared to other existing sensors, which are commonly made of silicon and indium antimonide, the group's hybrid sensor displayed much higher sensitivity to magnetic fields.

In particular, when measured at 127 degree Celsius (the maximum temperature which most electronics products are operated at), the researchers observed a gain in sensitivity of more than eight-fold over previously reported laboratory results and more than 200 times that of most commercially available sensors.

The study was published in the journal Nature Communications.