Titanium Dioxide as a Nanoscale Sensor of Mechanical Stress
July 31, 2018 | EPFLEstimated reading time: 2 minutes
Scientists from EPFL, Germany and France have revealed a new property of the cheap and abundant material anatase titanium dioxide, which promises applications as a medium for room-temperature nanosensors of mechanical stress with an optical read-out.
Image Caption: The ultrafast two-dimensional deep-ultraviolet spectroscopy setup at EPFL used for the experiments on anatase TiO2 nanoparticles. Credit: Francesco Pennacchio
Measuring mechanical stress in the nano-world is a major challenge in materials science and engineering. Key to this advancement is the ability to combine cheap nano-sized materials that react to mechanical stress and simple detection schemes. A promising route would involve the development of sensors with an optical read-out. However, there are no known nano-materials that change their light-absorbing properties upon application of mechanical stress in a simple and predictable way, especially at room temperature. Such materials would be extremely useful in a number of sensing applications, ranging from bioscience to metrology.
In a twist, the lab of Majed Chergui at EPFL within the Lausanne Centre for Ultrafast Science, in collaboration with the theoretical groups of Angel Rubio at Max-Planck (Hamburg) and Pascal Ruello at the Université de Le Mans, has demonstrated that nanoparticles of the anatase polymorph of titanium dioxide can revolutionize the field.
Titanium dioxide is a cheap and abundant material that is already used in a wide variety of applications such as photovoltaics, photocatalysis, transparent conductive substrates, sunscreen, paints, water and air purification. With their recent discovery, published in Nano Letters, Chergui and his colleagues show that titanium dioxide is the most promising candidate for the development of room-temperature sensors of strain at the nanoscale and with an optical read-out.
In their experiments, the researchers launched a mechanical stress wave inside titanium dioxide nanoparticles at room temperature and monitored their optical response in the vicinity of the main absorption band of the material, called an “exciton”. They found that the latter undergoes a change of intensity under the applied mechanical stress. This simple response is at odds with the behavior of all known materials, whose optical responses to mechanical stress are complex and unpredictable. These new findings pave the way to the development of sensors with an optical read-out based on a single laser frequency tuned to the exciton resonance.
Considering that titanium dioxide is already embedded in a large range of devices and there is wide expertise available for combining it with other systems, these findings promise a new generation of optical sensors of mechanical stress at the nanoscale.
“This observation was made possible thanks to our novel ultrafast laser techniques in the deep-ultraviolet. We expect our experimental method to lead to even more exciting discoveries in the nano-world in the near future,” says Edoardo Baldini (first author of the article, now at MIT).
Suggested Items
Groundbreaking Ceremony Marks the Beginning of a New Era for Newccess Industrial; The Construction of the MINGXIN Building
04/12/2024 | Newccess IndustrialOn a clear and sunny day in March, the groundbreaking ceremony for the MINGXIN Building took place in Shenzhen, China. This moment marked the official commencement of construction for a project that will reshape the semiconductor materials industry.
The Need for a Holistic Global Sustainability Standard
04/10/2024 | Michael Ford, Aegis SoftwareNo one can deny that the resources of our fragile planet are finite. The environment seems like a third party, subject to constant degradation. We’re acutely aware of the effects of pollution on our climate, and despite our “throw-away” culture, recycling and recovery of materials has remained relatively expensive, even as we use more energy just to survive.
iNEMI Publishes Four Roadmap Topics
04/04/2024 | iNEMIThe International Electronics Manufacturing Initiative (iNEMI) announces the availability of the first roadmap topics in the new iNEMI Roadmap format. Printed circuit boards, sustainable electronics, smart manufacturing, and mmWave materials and test are now available online.
Insulectro’s 'Storekeepers' Extend Their Welcome to Technology Village at IPC APEX EXPO
04/03/2024 | InsulectroInsulectro, the largest distributor of materials for use in the manufacture of PCBs and printed electronics, welcomes attendees to its TECHNOLOGY VILLAGE during this year’s IPC APEX EXPO at the Anaheim Convention Center, April 9-11, 2024.
Checking In With ICAPE Group
04/03/2024 | Nolan Johnson, I-Connect007ICAPE Group’s field application engineer Erik Pederson drills down on sustainability, supply chain resiliency, and what value engineering really looks like in this exclusive interview. Founded in 1999, European-based ICAPE Group provides 21 million printed circuit boards and over six million technical parts to manufacturers every month. With 30 PCB manufacturing partners globally and 50 partners providing a wide array of technical parts, ICAPE Group has operations in China, Taiwan, Thailand, South Korea, Vietnam, South Africa, Europe, Mexico, and the United States. The company also focuses on the value proposition for its customers.