A new hybrid magnetic sensor that is over 200 times more sensitive than most commercially available sensors has been developed by scientists, including those of Indian-origin.
A new hybrid magnetic sensor that is over 200 times more sensitive than most commercially available sensors has been developed by scientists, including those of Indian-origin.
The technological breakthrough hails opportunities for the development of smaller and cheaper sensors for various fields such as consumer electro-nics, information and co-mmunication technology, biotechnology and automotive. 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 developed by a team led by associate professor Yang Hyunsoo from National University of Singapore (NUS) may finally meet these requirements. The 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. “We started by trying to understand how graphene responds under the magnetic field,” said Dr Kalon Gopinadhan of NUS. “We found that a bilayer structure of graphene and boron nitride displays an extremely large response with magnetic fields. This combination can be utilised for magnetic field sensing applications,” added Kalon.
