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“Smart skin” can identify weaknesses in bridges and airplanes using laser scanner
Recent research results have demonstrated that two-dimensional, on-demand mapping of the accumulated strain on metal structures will soon be a reality thanks to an engineered “smart skin” that’s only a fraction of the width of a human hair. By utilizing the unique properties of single-walled carbon nanotubes, a two-layer film airbrushed onto surfaces of bridges, pipelines, and airplanes, among others, can be scanned to reveal weaknesses in near real-time. As a bonus, the technology is barely visible even on a transparent surface, making it that much more flexible as an application.
Stress-inducing events, along with regular wear and tear, can deform structures and machines, affecting their safety and operability. Mechanical strain on structural surfaces provides information on the condition of the materials such as damage location and severity. Existing conventional sensors are only able to measure strain in one point along one axis, but with the smart skin technology, strain detection in any direction or location will be possible.
How “Smart Skin” Technology is Used
In 2002, researchers discovered that single-wall carbon nanotubes fluoresce, i.e., glow brightly when stimulated by a light source. Later, the fluorescence was further found to change color when stretched. This optical property was then considered in the context of metal structures that are subject to strain, specifically to apply the property as a diagnostic tool. To obtain the fluorescent data, researchers applied the smart skin to a testing surface, irradiated the area with a small laser scanner, and captured the resulting nanotube color emissions with an infrared spectrometer. Finally, two-dimensional maps of the accumulated strain were generated with the results.
The primary researchers, Professors Satish Nagarajaiah and Bruce Weisman of Rice University in Texas, have published two scientific papers explaining the methods used for achieving this technology and the results of its proof-of-principle application. As described in the papers, aluminum bars with holes or notches in areas of potential stress were tested with the laser technique to demonstrate the full potential of their invention. The points measured were located 1 millimeter apart, but the researchers stated that the points could be located 20 times closer for even more accurate readings. Standard strain sensors have points located several millimeters apart.
What Are Carbon Nanotubes?
Carbon nanotubes (CNTs) are carbon molecules that have been structurally modified into cylinders, or rather, rolled up sheets of carbon atoms. There has been some evidence suggesting that CNTs can be formed via natural processes such as volcanic events. However, to really capitalize on their unique characteristics, production in a laboratory environment is much more efficient.
Several methods can be used for production, but the most widely used method for synthesizing CNTs is chemical vapor deposition (CVD). This process combines a catalyzing metal with a carbon-containing gas which are heated to approximately 1400 degrees Fahrenheit, triggering the carbon molecules to assemble and grow into nanotubes. The resulting formation resembles a forest or lawn grass, each trunk or blade averaging .43 nanometers in diameter. The length is dependent on variables such as the amount of time spent in the high heat environment.
Besides surface analysis, carbon nanotubes have proven invaluable in many research and commercial arenas, their luminescence being only one of many properties that can improve and enable other technologies. Their mechanical tensile strength is 400 times that of steel while only having one sixth the density, making them very lightweight. CNTs also have highly conductive electrical and thermal properties, are extremely resistant to corrosion, and can be filled with other nanomaterials. All of these advantages open up their applications to include solar cells, sensors, drug delivery, electronic devices and shielding, lithium-ion batteries, body armor, and perhaps even a space elevator, assuming significant advances overcome its hurdles.
Next Steps
The nanotube-laced smart skin is ready for scaling up into real-world applications, but its chosen industry may take time to adopt given the general resistance to change in a field with long-standing existing technology. While awaiting embrace in the arena it was primarily designed for, the smart skin has other potential uses in engineering research applications. Bruce Weisman, also the discoverer of CNT fluorescence, anticipates its advantages being used for testing the design of small-scaled structures and engines prior to deployment. Niche applications like these may be the primary entry point into the market for some time to come. In the meantime, the researchers plan to continue developing their strain reader to capture simultaneous readings from large surfaces.
Tesla has updated its Robotaxi app so riders can pick which vehicle they want before they book. The latest in-app screens now show two options side by side: the two-seat Cybercab and the four-seat Model Y.
A screenshot circulating Thursday shows the change in practice. In Austin, a rider could choose a gold Cybercab for two people or a Model Y for four. Tesla’s updated description calls Cybercab “our first purpose-built autonomous vehicle,” designed for safety, accessibility, and comfort, and says the lineup is available only through the Robotaxi app.
Tesla has updated their Robotaxi page in the App Store. You’ll be able to select if you want a Cybercab or Model Y Robotaxi.
“Our Robotaxi vehicle lineup now includes Cybercab, our first purpose-built autonomous vehicle. Designed for safety, accessibility and comfort, Cybercab… pic.twitter.com/Jff4klilDr
— Sawyer Merritt (@SawyerMerritt) September 3, 2026
The distinction is more than cosmetic, and it’s important to note that Robotaxi refers to the platform, while Cybercab refers to a vehicle.
Model Y Robotaxis have carried the service since it opened in Austin in mid-2025 and later expanded to Dallas, Houston, and parts of Florida. Those vehicles are converted production SUVs that still have steering wheels and pedals.
Cybercab is different. It has no driver controls, butterfly doors, a low seat height meant to work with wheelchairs, extra trunk space for assistive devices, and braille on the handles. Tesla has registered dozens of the two-seaters with Texas regulators in the days leading up to its September 3 Austin event.
Giving riders a choice lets Tesla match the vehicle to the trip. Most rides involve one or two people, which is where Cybercab is meant to be cheaper and more efficient to operate. Groups of three or four, or anyone who needs more space, can still request a Model Y.
The same app handles booking, payment, cabin settings, and, on Cybercab, features such as phone-based door opening and in-cabin voice controls.
The update does not mean every city suddenly has both cars available. Cybercab support is listed for Austin first, and the purpose-built fleet is still small compared with the existing Model Y roster. Even so, the app change marks a shift from a single-vehicle pilot to a mixed fleet.
Riders can now choose between the compact, purpose-built robotaxi and the familiar SUV that launched the service.
Tesla Cybercab sightings are broadening far and wide, well outside of downtown Austin, Texas, with autonomy in focus as the company plans to launch the all-electric, two-seater this evening in the Lone Star State.
Tesla is set to launch Cybercab to a small group of people this evening in a dedicated event in Austin, Texas. Public details on the event are relatively slim.
However, Tesla’s focus on Cybercab falls well outside of the downtown Austin area and is expanding well across the United States as things continue to move quickly with the company’s autonomous efforts in 2026. Today, various images of Cybercab fleets in interesting locations have started to circulate.
The most notable is a fleet of at least 20 Cybercabs at Miami International Airport in Florida. Spotted last night, the fleet is expansive and is indicative of a looming release of Cybercabs once regulatory boxes are checked off.
Tesla has already been operating the Robotaxi platform in Miami for several months, but this Cybercab fleet at the airport could be joining the ride-hailing platform as approvals arrive:
20+ Cybercabs spotted near Miami international airport. pic.twitter.com/ORLsw8yFhf
— Sawyer Merritt (@SawyerMerritt) September 3, 2026
Another fleet of Cybercabs was spotted at the Devon, PA showroom just outside of Philadelphia. We have seen several Cybercab units testing around the Philadelphia Metro Area, which is interesting considering Tesla does not have any active Robotaxi geofence in Pennsylvania.
Cybercab at the Devon location in PA has multiplied over the weekend. Seeing a few more test vehicles in the lot 👀 pic.twitter.com/DhJT4P1EkU
— Billy (@billykyle) August 22, 2026
Philadelphia would be an ideal location to test ride-hailing due to its dense tourist population, large, sprawling city layout, and to compete with other ride-hailing companies that operate in the city.
Expansive fleets of Cybercabs will be popping up in and around major cities throughout the rest of the year, if we were betting on it. Tesla has made it obvious that the Cybercab rollout will be aggressive and fast-paced, but within reason. Tesla is still prioritizing safety, so these testing phases will likely go on for some period of time before more members of the public are able to snag a Cybercab for a personal chariot.
The Tesla Model Y L is arguably the most hyped trim of the all-electric crossover, other than the Performance configuration that comes with white-knuckle speed and sports car-level handling.
However, it is not all perfect. Tesla owners in China who took delivery of the Model Y L, denoted with an L to highlight its longer wheelbase, are experiencing what they are referring to as “collapsing” of the rear wheels, as suspension issues appear to be an issue with some of the builds.
🚨 Model Y L owners in China report rear suspension sag
• Six-seat long-wheelbase Y. Shanghai. On sale since August 2025
• Owners say the rear tire-to-arch gap shrinks after mileage or a full load. Some cases after about 9,000 km loaded. Others near 30,000 km
• Tesla service… pic.twitter.com/Lr6i5Tbi07— Joe Hansen (@joehansen) September 1, 2026
The gap between the wheel arch and tire has narrowed to the point that “not even a single finger” could fit, according to a report from Car News China. The failures are not tied to a specific mileage, as one owner said that after just 9,000 kilometers (5,600 miles), they noticed the suspension issue when their car was fully loaded.
Another one had the issue at 30,000 kilometers (18,640 miles) and noticed that the wheel gap shrank to two fingers, so not as drastic as the person who reported a similar issue at 9,000 km.
Tesla Model Y L is gaining momentum in China’s premium segment
Along with the visual recognition of the issue, others are saying the sagging is causing abnormal wear on the inside of the tires. Extra weight and instant torque already provide additional stress on the tires in electric vehicles during normal operation, so it is no surprise that this is another complaint.
There has been no recall issued by Tesla, and the company has not yet publicly acknowledged the issue.
Some are suggesting that owners use a “finger test” to self-diagnose whether there is an issue with the suspension. There should be four fingers between the tire and the wheel well; anything less than that starts to get dicey.
Tesla Robotaxi riders will face the best dilemma when booking a ride
Tesla Cybercab sightings broaden well outside of Austin with autonomy in focus
