Manufacturing Bits: Oct. 20

Thermometers for 3D measurements
The National Institute of Standards and Technology (NIST) is developing a nano-thermometer technology that could one day take 3D temperature measurements at the microscopic scale.

The project, called Thermal Magnetic Imaging and Control (Thermal MagIC), hopes to develop tiny thermometers based on magnetic nanoparticles. These tiny thermometers could be injected or built into a system, enabling precise 3D temperature measurements within an opaque object. If successful, the system will be the first to make real-time measurements of temperature on the microscopic scale in opaque 3D volume objects, which could include medical implants, refrigerators and even the human body, according to NIST.

Source: NIST

Other applications include biology, medicine, chemical synthesis, automotive and other fields.

Temperature impacts every physical system. Today’s thermometers measure relatively big areas on a macroscopic scale, according to NIST. Used in doctor’s offices, infrared thermometers make macroscopic measurements, but they cannot see beneath surfaces, according to NIST.

NIST is developing a different technology, which allows for remote temperature measurements within solid objects. These measurements are difficult, if not impossible, using existing probe-based or optical methods.

NIST’s thermometer is based on the temperature-dependent nature of magnetic nanoparticles. The magnetic particles are based on cobalt-doped ferrites.

NIST’s system consists of three elements: magnetic nano-objects (MNOs) with high thermal sensitivity; a magnetic drive and sensing instrument; and a technique for traceable extraction of temperature from the magnetic response of the MNOs.

The nano-thermometer could be injected or embedded in an object. In theory, the system could measure temperatures from 200 to 400 kelvin (K), which is about -99 to 260 degrees Fahrenheit (F). It also enables microscale spatial resolution and 25mK accuracy within measurement times of 0.1 second in optically hidden volumes of solid composites, complex fluids and biological systems, according to NIST.

It could make temperature measurements that are 10 times more precise than today’s techniques in one-tenth the time. This equates to measurements accurate to within 25 millikelvin (thousandths of a kelvin) in as little as a tenth of a second.

“Thermometry based on magnetic nanoparticles (MNPs) is an emerging technology that allows for remote temperature measurements throughout a volume that are impossible to achieve using conventional probe-based or optical methods. These improved nanothermometers form the basis of our effort to develop a practical means for spatially resolved, 3D, high-sensitivity measurements of temperature based on AC magnetometry.” said Adam Biacchi from NIST in the International Journal on Magnetic Particle Imaging. Others contributed to the work.

Quantum thermometers
Trinity College Dublin is developing a quantum thermometer that could potentially measure temperatures a billion times colder than those in outer space.

Researchers have demonstrated an in-situ thermometer technology using a cold Fermi gas. Fermi gases are ultra-cold temperatures that arise in clouds of atoms. They are created by scientists to study how matter behaves in extreme quantum states.

“A thermometer is just a system whose physical properties change with temperature in a predictable way. For example, you can take the temperature of your body by measuring the expansion of mercury in a glass tube. Our thermometer works in an analogous way, but instead of mercury we measure the state of single atoms that are entangled (or correlated) with a quantum gas,” said Giacomo Guarnieri from Trinity College Dublin.

In a separate development, Osaka City University, Keio University, Kyoto University and others have demonstrated a precise microscope-based thermometer based on quantum technology.

Using a quantum technology to probe temperatures on a nanometer-scale, researchers observed a fever-like condition in tiny worms.