Lots of single-use water bottles made from poly(ethylene terephthalate) (PET) end up in landfills, but there’s a growing interest in upcycling them instead. Researchers in Energy & Fuels report on new heat-based fabrication methods to transform PET into supercapacitor electrodes and separator films for upcycled energy storage devices. In demonstrations, an all-plastic supercapacitor made from discarded water bottles outperformed a similar design that used a traditional glass fiber separator.

“PET is used to produce over 500 billion single-use beverage bottles each year, which generates a significant amount of plastic waste and poses a major environmental challenge,” says lead researcher Yun Hang Hu. “PET-derived supercapacitors hold great potential for diverse applications in transportation and automotive systems, electronics and consumer devices, as well as industrial and specialized sectors.”

Converting waste plastics like PET into carbon-based materials, especially ones that are electrically conductive, is an attractive way to manufacture more cost-effective and sustainable energy storage devices like supercapacitors. These devices use highly conductive carbon electrodes to store and release a large amount of energy quickly and repeatedly. So, Hu and colleagues wanted to upcycle old water bottles into components for a type of supercapacitor called an electrical double-layer capacitor (EDLC). This device is characterized by two porous carbon-based electrodes separated by a thin, perforated film immersed in a liquid electrolyte.

Hu’s team developed two processes to turn used PET water bottles into components for the upcycled device:

• For the electrodes, the researchers cut the plastic bottles into tiny, couscous-sized grains. They added calcium hydroxide and heated the mixture to nearly 1300 degrees Fahrenheit (700 degrees Celsius) in a vacuum. This process converts the plastic into a porous, electrically conductive carbon powder. The researchers combined the carbon powder, carbon black and a polymer binder, and then dried it into thin layers.
• For the separator, the researchers flattened small plastic pieces about the size of postage stamps and poked holes in them using hot needles. The holes’ pattern optimized the passage of current through the electrolyte.

To assemble their PET-based supercapacitor, the researchers submerged two porous carbon electrodes in a liquid potassium hydroxide electrolyte and separated them with the perforated PET film. In demonstrations, the upcycled supercapacitor retained 79% of its capacitance (storage ability), while a similar device with a glass fiber separator retained 78%.

Hu and colleagues say this research introduces a potential strategy for transforming PET waste into supercapacitor components, “opening new opportunities for circular energy storage technologies.” In addition, they say the upcycled EDLC is less expensive to produce than devices made with glass fiber and is itself fully recyclable.

“With further optimization, PET-derived supercapacitors might realistically transition from laboratory prototypes to market-ready devices within the next five to 10 years,” says Hu, “especially as demand grows for sustainable, recyclable energy storage technologies.”

Everyone who enters the fabs has to wear a bunny suit, and get dressed—or be dressed—in a clean room. Makeup, hair products, perfumes, colognes, and any aerosol products are prohibited. Workers are separated by a metallurgical hierarchy: There are those who work with copper, and those who do not. The copper people wear orange suits, not white, and have to suit up and strip down in their own clean room.

The Intel fab worker who helped me suit up proudly told me that he has done the same for two US presidents: Obama, who visited Fab 42, and Biden, who visited Fab 52 while it was under construction. As of late September, Trump still hadn’t visited, though Intel spokesperson Cory Pforzheimer said, “We’d eagerly welcome President Trump to see the most advanced R&D and leading-edge semiconductor manufacturing in the US.”

The workers shuffling around are not pulling levers and grinding away at the gears of manufacturing as much as quietly managing robots. They stand at (sterilized) computer stations while containers called front-opening unified pods, or FOUPs, whoosh by overhead through a labyrinth of robotic tracks. The rows of equipment appear endless. The floor below has been reinforced, then reinforced again, because the tiniest of shakes can ruin a whole batch of chips.

The lithography section of the facility is awash in a strange glow, which turned our white suits neon green and the copper-suited people pink. Intel demanded that the fab tourists not share the names of its suppliers, with the exception of one: ASML, the Dutch manufacturer of the world’s most cutting-edge lithography machines. WIRED witnessed two massive ASML Twinscan machines that appeared to be operational. The floor next to them was tape-marked with space for two more.

Intel has not yet publicly said how many semiconductors it expects to successfully yield, or manufacture, at Fab 52 annually. For now, the chips produced there will be used in consumer devices like laptops. But what Intel really needs is the same thing the entire industry is chasing: A hyperscaler customer, a giant data center deal, someone looking to spend billions to get an edge in AI. A whale.

Design Overhaul

Intel’s Panther Lake and Clearwater Forest chips will be made using a manufacturing process that tosses aside decades of proven design techniques in favor of two new technologies the company calls RibbonFET and PowerVia. RibbonFet is an architecture for transistors, stacking them in a way that allows for more density, while PowerVia moves the power interconnects from above the silicon stacks in the chip to below them.

Intel began working on the new design approach in 2021, and early tests have shown that RibbonFet and PowerVia led to performance gains. Reports suggest these new chips also use 30 percent less energy than the prior generation.

iPhone users have a new tool to combat the scourge of nuisance phone calls: a virtual gatekeeper that can screen incoming calls from unknown numbers.

It’s among the bevy of new features that Apple rolled out with last month’s release of iOS 26. The screening feature has been getting attention because of the ever-increasing amount of robocalls and spam calls that leave many phone users feeling harassed.

Here’s a run-through of the new function:

How to activate call screening

First, you’ll need to update your iPhone’s operating system to iOS 26, which is available to the iPhone 11 and newer models.

To switch call screening on, go into Settings—Apps—Phone. Scroll down and you’ll find a new option: Screen Unknown Callers.

You’ll be presented with three choices. The Never option lets any unknown call ring through, while Silence sends all unidentified numbers directly to voicemail. What you want to tap is the middle option: Ask Reason for Calling.

If the option isn’t there, try restarting your phone.

I still couldn’t find it after updating to iOS 26, but, after some online sleuthing, I checked my region and language settings because I saw some online commenters reporting they had to match. It turns out my region was still set to Hong Kong, where I lived years ago. I switched it to the United Kingdom, which seemed to do the trick and gave me the updated menu.

How it works

Call screening introduces a layer between you and new callers.

When someone who’s not in your contacts list dials your number, a Siri-style voice will ask them to give their name and the purpose of their call.

At the same time, you’ll get a notification that the call is being screened. When the caller responds, the answers will be transcribed and the conversation will pop up in speech bubbles.

You can then answer the call.

Don’t want to answer? Send a reply by tapping one of the pre-written messages, such as “I’ll call you later” or “Send more information,” which the AI voice will read out to the caller.

Or you can type out your own message for the computer-generated voice to read out.

If you don’t respond right away, the phone will continue to ring while you decide what to do.

Teething troubles

In theory, call screening is a handy third way between the nuclear option of silencing all unknown callers—including legitimate ones—or letting them all through.

But it doesn’t always work perfectly, according to Associated Press colleagues and anecdotal reports from social media users.

One AP colleague said she was impressed with how seamlessly it worked. Another said it’s handy for screening out cold callers who found his number from marketing databases.

“However, it’s not great when delivery drivers try to call me and then just hang up,” he added.

Some internet users have similar complaints, complaining that important calls that they were expecting from their auto mechanic or plumber didn’t make it through. Perhaps the callers assumed it was an answering machine and didn’t seem to realize they had to stay on the line and interact with it.

I encountered a different issue the first time it kicked in for me, when an unknown caller—whether mistakenly or not—threw me off by giving my name instead of theirs. So I answered because I assumed it was someone I knew, forgetting that I could tap out a reply asking them again for their name.

The caller turned out to be someone who had obtained my name and number and was trying to get me to do a survey. I had to make my excuses and hang up.

If you don’t like call screening, you can turn it off at any time.

As for Android

Apple is catching up with Google, which introduced a similar automatic call screening feature years ago for Pixel users in the United States.

Last month, the company announced the feature is rolling out to users in three more countries: Australia, Canada and Ireland.

If it’s not already on, go to your Phone app’s Settings and look for Call Screen.

Google’s version is even more automated. When someone you don’t know calls, the phone will ask who it is and why they’re calling. It will hang up if it determines that it’s a junk call, but let calls it deems to be legit ring through.

Google warns that not all spam calls and robocalls can be detected, nor will it always fully understand and transcribe what a caller says.

Samsung, too, lets users of its Galaxy Android phones screen calls by using its AI assistant Bixby’s text call function, which works in a similar way.

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