Last updateThu, 01 Jun 2023 12pm

Back You are here: Inicio New materials Technological offers A temperature sensor in a wire

A temperature sensor in a wire

Scientists have developed a temperature sensor based on materials that deform with high temperatures. It is a microwire coated with concentric layers of different materials. Very small, it is a few millimeters larger and has a diameter of 40 micrometers.

Materials that deform when temperature changes are promising for technological uses. Scientists at the Instituto de Ciencia de Materiales de Madrid (CSIC) and the Slovak University of Technology (Bratislava), have developed a new sensor of temperature based on this type of materials.

The sensor is composed of a metallic microwire and several concentric layers made of different materials, conductors and insulators. The mechanical and magnetic properties of these materials are different and therefore they react differently when temperature increases. The proper combination of these layers enables the best magnetic and mechanical properties. It has, also, radial asymmetry in any transversal section of its structure, which confers its functionality.

Picture of the device (left), which deforms proportionally to temperature increases. Diagram at the right: With a small electric current of milliamps, there is a temperature rise of grades.

The device, which is only 5 to 10 millimeters large and 40 micrometers diameter, can be applied in electromechanical sensors to control the working temperature of virtually any machine or device. It can be used in microdevices, for the control of artificial muscles in robotics, for flow control valves in refrigerators and magnetic-mechanical systems.

How does it work? Through the wire passes an electric current whose amplitude and frequency is controlled. When the temperature rises (either the environmental temperature or the temperature released by the electrical current through the microwire), the layers deform. The deformation depends on each material’s thermal expansion coefficient. This mechanical reaction is strongly determined by the mechanical tensions generated during the  production of these materials.

Tests in laboratory have allowed the scientists to confirm that when the temperature increases, the layers suffer a proportional deformation, and when the temperature goes back to the starting point, they recover the previous shape.

The sensor can be connected two ways: either connecting both endings to electrical contacts or only one of the endings. Among its main advantages, its high sensitivity and velocity for measuring temperature changes, the small size and a simple process for the production of the coated microwire.


Marisa Carrascoso Arranz
Vicepresidencia Adjunta de
Transferencia del Conocimiento- CSIC
Tel.: + 34 – 91 568 15 33 This email address is being protected from spambots. You need JavaScript enabled to view it.