The newly developed all-optical nanosensor is a luminescent nanocrystal that changes intensity and color when pushed or pulled. Probed only with light, allowing fully remote reading. No wires or connections required. They have force sensitivity that is 100 times better than existing nanoparticles that utilize rare earth ions for their optical response, with a force operating range of more than four orders of magnitude and a much wider range than other nanoparticles (10–100 times). Conventional optical nanosensor.

“Our discovery revolutionizes the sensitivity and dynamic range achievable with optical force sensors, and has implications for applications from robotics to cellular biophysics, medicine to space travel,” said Dr. Jim Shack, a researcher at Columbia University. We expect that this technology will immediately disrupt technology in this field.”

The new nanosensor enables high-resolution, multiscale capabilities for the first time in the same nanosensor.

This means that this nanosensor alone, rather than a series of different classes of sensors, can be used for the continuous study of forces from the subcellular level to the whole system level in engineered and biological systems such as embryonic development. It is important because it means , moving cells, batteries, or integrated NEMS, highly sensitive nanoelectromechanical systems in which the physical movement of nanometer-scale structures is controlled by electronic circuits and vice versa.

“Aside from their unparalleled multiscale sensing capabilities, what makes these force sensors unique is that they operate with benign, biocompatible, and deeply penetrating infrared light,” said Natalie, a postdoctoral fellow at Columbia University. said Dr. Fardian Melamed.

“This will allow us to peer deeply into various technical and physiological systems and monitor health conditions from a distance.”

“These sensors will enable early detection of system malfunctions and failures, and will have a major impact on sectors ranging from human health to energy and sustainability.”

Researchers were able to construct these nanosensors by exploiting the photon avalanche effect within nanocrystals.

In photon avalanche nanoparticles, the absorption of a single photon within the material causes a chain reaction that ultimately leads to the emission of many photons. Therefore, one photon is absorbed and many photons are emitted.

The optically active components within the nanocrystals studied are atomic ions from the lanthanide series of elements of the periodic table, also known as rare earth elements, doped into the nanocrystals. In this study, the scientists used thulium.

They found that the photon avalanche process is very sensitive to several things, such as the spacing between lanthanide ions.

With this in mind, they tapped a piece of a photon avalanche nanoparticle (ANP) with an atomic force microscope (AFM) tip and found that the avalanche's behavior was influenced by these gentler forces than previously expected. I found that I was greatly affected.

“We discovered this almost by accident,” Shook said.

“We suspected that these nanoparticles were force-sensitive, so we measured the release while hitting the nanoparticles.”

“And they turned out to be much more sensitive than expected!”

“In fact, we couldn't believe it at first either. We thought the chip might be having a different effect.”

The authors knew how sensitive ANPs were, so they designed new nanoparticles that responded to force in different ways.

In one new design, nanoparticles change the color of their emitted light depending on the applied force.

In another design, they created nanoparticles that do not exhibit photon avalanches under ambient conditions, but start avalanching when a force is applied. These turned out to be very sensitive to forces.

They are now applying these force sensors to critical systems with the goal of making a big impact.

“The importance of developing new force sensors was recently highlighted by 2021 Nobel Prize Laureate Erdem Patapoutian. “It highlighted the difficulty of investigating biological processes,” said Dr. Shook.

“We are thrilled to be part of these discoveries that will transform the sensing paradigm and allow us to sensitively and dynamically map significant changes in forces and pressures in real-world environments that are unreachable with today's technology.” I think so.

team's work Published in today's diary nature.

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Natalie Fardian Melamed others. 2025. Infrared nanosensor from piconewton to micronewton forces. naturein press. doi: 10.1038/s41586-024-08221-2

This article is a version of a press release provided by Columbia University.