Can a three-hour workshop on advanced material analysis techniques turn someone into a detective – or maybe an art conservator?
In slow January, at MIT’s Center for Bits and Atoms (CBA), a dozen students explored this possibility during an Independent Activity Period (IAP) workshop on Raman spectroscopy, a technique that uses laser lightweight to create “fingerprints” on materials. The session even featured a robot dog equipped with sensors, demonstrating how chemical analysis can be performed remotely.
The workshop, led by MIT postdoctoral fellow Lamyaa Almehmadi in collaboration with CBA, introduced participants to the advanced technology currently used by law enforcement and emergency services to identify drugs and explosives, by gemologists to authenticate gemstones, and by pharmaceutical companies to verify raw materials and ensure product quality. CBA graduate researcher Jiaming Liu co-hosted, lectured, demonstrated Raman equipment, and participated in curriculum and hands-on demonstrations.
“It could open up new opportunities for innovation in many fields,” said Almehmadi, an analytical chemist at the Department of Materials Science and Engineering (DMSE). Once participants learned the basics, she encouraged them to think creatively about fresh applications: “I hope to inspire you all to think about doing something with Raman spectroscopy that no one has ever done before.”
Fingerprint materials
Participants brought objects to class to be analyzed using portable devices that emit laser lightweight and measure how it reflects. The resulting pattern acts like a molecular fingerprint, identifying the materials contained in the object – whether it is a paper clip, a piece of tree bark or a mixing bowl.
Workshop participant Sarah Ciriello, an administrative assistant at DMSE who brought the stone found on the beach, was surprised by the results. The Raman device suggested a 39 percent probability that the sample contained a concrete-like material, with the remaining readings corresponding to synthetic compounds, blurring the line between natural and artificial materials.
“It’s man-made. I was surprised,” Ciriello said.
Developed in 1928 by Indian scientist CV Raman, who later won the Nobel Prize in Physics, Raman spectroscopy was groundbreaking because it used perceptible lightweight to study materials without destroying them, a major advantage over other techniques of the time such as chromatography or mass spectrometry. But for decades, the Raman signal – the lightweight scattered from the sample – was faint and the instruments were vast and cumbersome, limiting their practical apply.
Advances in lasers, computing power, and miniaturized optics have transformed Raman spectroscopy into a portable tool. Today’s mobile devices can instantly compare a sample’s molecular fingerprint against expansive digital libraries, enabling users to identify thousands of materials in seconds. Because it does not destroy the sample, the Raman method is particularly useful in areas that require material preservation – such as law enforcement, where evidence must remain intact, and art restoration.
Almehmadi’s own research focuses on advancing Raman spectroscopy by developing highly sensitive semiconductor sensors that enable portable chemical analysis in applications ranging from medical diagnostics to forensics and environmental monitoring.
“Raman can be used to analyze any material,” Almehmadi says. “That’s why I decided to introduce it to students from different backgrounds.”
IAP classes are open to students and staff across MIT, and Raman’s workshops reflected that range – from administrative staff to graduate and undergraduate students and postdoctoral students in departments and laboratories including DMSE, the Department of Mechanical Engineering, the Media Lab, and the Broad Institute.
Walking with a robot dog
A nice element of the workshop for the audience was the integration of a robot dog belonging to the Computer Science and Artificial Intelligence Laboratory (CSAIL) at MIT. The demonstration showed how Raman technology can be used in hazardous environments such as crime scenes or toxic industrial facilities.
The handheld device was attached to the robot with tape, and Almehmadi showed how to lead the dog to a plastic bag filled with a white powder – baking soda.
But in a real scenario, “How can we know if it’s baking soda or not?” she says. “So we just turned on the light and the instrument told us what it was.”
Participants used a Wi-Fi app on their phones to view results and a miniature remote control to independently control the robotic dog.
“I loved the robot dog,” Ciriello says. “I was able to control it a little bit, but it was difficult because the indicator was really sensitive.”
Michael Kitcher, a postdoc at DMSE, also praises the robot’s demonstration.
“Considering we had just taped the device to the dog, it was cool to see how it actually worked,” he says.
Looking to the future
Kitcher, who studies magnetic materials for electronics applications, joined the workshop to learn more about Raman spectroscopy, which he had read about but had never used. He was impressed by its versatility—in addition to beach rock and baking soda, the device identified materials in contact lenses, cosmetics, and even diamond.
Although analyzing the piece of chocolate he brought back was arduous – he was hampered by other signals coming from the chocolate – Kitcher sees great potential for his own research. One of his areas of interest is unconventional magnetic materials, such as altermagnets, with unusual magnetic behavior that researchers hope to better understand and control to achieve more energy-efficient electronics.
“Over the last few years, people have been trying to better understand why these materials behave the way they do – how we can control this unconventional magnetic order,” he says. Raman spectroscopy can study the vibrations of atoms in a material, helping scientists detect patterns in the crystal structure that underlie unusual magnetic behavior. By understanding these vibrations, scientists could discover material design principles that enable ultrafast, low-power computing.
These kinds of hands-on workshops that inspire creative future applications, Almehmadi says, are at the heart of an MIT education.
“I have always learned best by doing,” she says. “Lectures and readings are important, but true understanding comes from practical experience.”