schwit1 shares a report from Threatpost: Quick-response (QR) codes used by a COVID-19 contact-tracing program were hijacked by a man who simply slapped up scam QR codes on top to redirect users to an anti-vaccination website, according to local police. He now faces two counts of "obstructing operations carried out relative to COVID-19 under the Emergency Management Act," the South Australia Police said in a statement announcing the arrest. His arrest may just be a drop in the bucket: Reports of other anti-vax campaigners doing the same thing abound. Law enforcement added an additional warning to would-be QR code scammers: "Any person found to be tampering or obstructing with business QR codes will likely face arrest and court penalty of up to $10,000." The police said no personal data was breached, but the incident highlights that truly all an attacker needs is a printer and a pack of Avery labels to do real damage.

In this case, the QR codes were being used by the South Australian government's official CovidSafe app to access a device's camera, scan the code and collect real-time location data to be used for contact tracing in case of a COVID-19 outbreak, ABC News Australia reported. That's a lot of personal data linked to a single QR code just waiting to be stolen. "In this instance, people who scanned the illegitimate QR code were redirected to a website distributing misinformation from the anti-vaxxer community," Bill Harrod, vice president of public sector at Ivanti, told Threatpost. "While this is concerning, the outcome could have been far more perilous."

Twitter user @mrcatacroquer, Manual Lucio Dallo, built the Yayagram -- a DIY project that makes sending and receiving voice and text messages over Telegram a physical process just like using an old-fashioned phone switchboard. Speaking to The Verge, Dallo says he built the machine to help stay in touch with his 96-year-old grandmother. From the report: To send a message, the user physically plugs in a cable next to the recipient's name. They then press and hold a button to record audio and speak into the integrated microphone. The message then appears on the recipient's phone like a regular voice note. And when the operator of the Yayagram receives a text message, it's printed off using a built-in thermal printer.

Dallo, who's a senior engineer for software firm Plastic SCM, goes into some detail about how the device was made in this Twitter thread. It's powered by a Raspberry Pi 4, runs on Python, and uses several third-party software libraries to tie everything together. The microphone is a cheap USB one and the printer similar to those used in cashier tills. He notes that he chose to use Telegram rather than WhatsApp or another messaging service as it's more open (and he doesn't like Facebook).

Cory Doctorow, writing at Wired: When we talk about social media monopolies, we focus too much on network effects, and not enough on switching costs. Yes, it's true that all your friends are already stuck in a Big Tech silo that doesn't talk to any of the other Big Tech silos. It needn't be that way: interoperable platforms have existed since the first two Arpanet nodes came online. You can phone anyone with a phone number and email anyone with an email address.

The reason you can't talk to Facebook users without having a Facebook account isn't that it's technically impossible -- it's that Facebook forbids it. What's more, Facebook (and its Big Tech rivals) have the law on their side: the once-common practice of making new products that just work with existing ones (like third-party printer ink, or a Mac program that can read Microsoft Office files, or an emulator that can play old games) has been driven to the brink of extinction by Big Tech. They were fine with this kind of "competitive compatibility" when it benefited them, but now that they dominate the digital world, it's time for it to die.

To restore competitive compatibility, we would need reform to many laws: software copyright and patents, the anti-circumvention laws that protect digital rights management, and the cybersecurity laws that let companies criminalize violations of their terms of service.

Long-time Slashdot reader destinyland writes: The New York Times tells the story of Hungarian-born Dr. Kariko, whose father was a butcher and who growing up had never met a scientist — but knew they wanted to be one. Despite earning a Ph.D. at Hungary's University of Szeged and working as a postdoctoral fellow at its Biological Research Center, Kariko never found a permanent position after moving to the U.S., "instead clinging to the fringes of academia."

Now 66 years old, Dr. Kariko is suddenly being hailed as "one of the heroes of Covid-19 vaccine development," after spending an entire career focused on mRNA, "convinced mRNA could be used to instruct cells to make their own medicines, including vaccines."
From the article: For many years her career at the University of Pennsylvania was fragile. She migrated from lab to lab, relying on one senior scientist after another to take her in. She never made more than $60,000 a year... She needed grants to pursue ideas that seemed wild and fanciful. She did not get them, even as more mundane research was rewarded. "When your idea is against the conventional wisdom that makes sense to the star chamber, it is very hard to break out," said Dr. David Langer, a neurosurgeon who has worked with Dr. Kariko... Kariko's husband, Bela Francia, manager of an apartment complex, once calculated that her endless workdays meant she was earning about a dollar an hour.
The Times also describes a formative experience in 1989 with cardiologist Elliot Barnathan: One fateful day, the two scientists hovered over a dot-matrix printer in a narrow room at the end of a long hall. A gamma counter, needed to track the radioactive molecule, was attached to a printer. It began to spew data.

Their detector had found new proteins produced by cells that were never supposed to make them — suggesting that mRNA could be used to direct any cell to make any protein, at will.

"I felt like a god," Dr. Kariko recalled.
Yet Kariko was eventually left without a lab or funds for research, until a chance meeting at a photocopying machine led to a partnership with Dr. Drew Weissman of the University of Pennsylvania: "We both started writing grants," Dr. Weissman said. "We didn't get most of them. People were not interested in mRNA. The people who reviewed the grants said mRNA will not be a good therapeutic, so don't bother.'" Leading scientific journals rejected their work. When the research finally was published, in Immunity, it got little attention... "We talked to pharmaceutical companies and venture capitalists. No one cared," Dr. Weissman said. "We were screaming a lot, but no one would listen."

Eventually, though, two biotech companies took notice of the work: Moderna, in the United States, and BioNTech, in Germany. Pfizer partnered with BioNTech, and the two now help fund Dr. Weissman's lab.

Following reports that a recent update to Windows 10 was causing blue screens as well as problems with printing, Microsoft issued a new series of updates to address the issues. But it seems that the problems caused by this month's Patch Tuesday updates are actually worse than first thought. BetaNews reports: Users with certain brands of printer experienced APC_INDEX_MISMATCH errors and blue screens, but now Microsoft has issued a warning that there may be additional problems with elements missing from print outs, or even entirely blank pages being output. The problematic updates are KB5000802, KB5000808, KB5000809 and KB5000822. In the support documentation for these four updates, Microsoft acknowledges the APC_INDEX_MISMATCH error problems and BSoDs, and directs people to install the relevant patches for their system. But the company now also acknowledges that there are more problems with the original updates than first appeared to be the case.

For each of these four updates Microsoft issues the same warning: "After installing updates released March 9, 2021 or March 15, 2021, you might get unexpected results when printing from some apps..." There is currently no fix, and Microsoft is not even able to offer a workaround right now. Instead, the company simply says: "We are working on a resolution and estimate a solution will be available in the coming days."

An anonymous reader quotes a report from Hackaday: Probably the best known brand of cutter comes from Cricut, and that company has dropped a bombshell in the form of an update to the web-based design software that leaves their now very annoyed users with a monthly upload limit of 20 new designs unless they sign up for a Cricut Access Plan that costs $9.99 on monthly payments. Worse still, a screenshot is circulating online purporting to be from a communication with a Cricut employee attempting to clarify matters, in which it is suggested that machines sold as second-hand will be bricked by the company.

We'd like to think that given the reaction from their online community the subscription plan will backfire, but unlike the world of 3D printing their market is not necessarily an online-savvy one. A crafter who buys a Cricut from a bricks-and-mortar warehouse store and uses it with Cricut cartridges may not balk at being required to pay rent to use hardware that's already paid for in the same way a member of our community with a 3D printer would. After all, Cricut have always tried to make their software a walled garden. However if the stories about second-hand models being bricked turn out to bear fruit that might be a different matter. UPDATE 3/18/21: Cricut has decided to reverse its decision and allow every member to upload an unlimited number of images and patterns for free.

"Right now, every member can upload an unlimited number of images and patterns to Design Space for free, and we have no intention to change this policy," a Cricut spokesperson told us in an email. "This is true whether you're a current Cricut member or are thinking about joining the Cricut family before or after December 31, 2021."

They addressed these changes in a letter to the Cricut community, which you can read here.

"Mighty Buildings is using robots and 3D printers to build a $15 million community of homes in California," reports Business Insider: Mighty Building's upcoming project in Rancho Mirage, California will have the title of "world's first planned community of 3D printed homes," according to its maker... The tech-forward housing development will consist of 15 homes across five-acres. This $15 million project will be built using the Mighty Kit system, which utilizes prefabbed panels to create custom homes.

Through this system, gone are the days of concrete. Instead, the homes will be based on Mighty Building's 3D printed proprietary Light Stone Material, which sets its shape upon UV light exposure, according to the company. The printers also rely on "robotic automation" and robotic arms, the latter for functions like quality control scans, Ruben told Insider in an email interview...

The 3D-printed homes won't look any different than a traditionally constructed mid-century modern home. The 1,450 square-foot homes — which will be placed atop 10,000-square-foot plots of land — will come with three bedrooms and two bathrooms. If that's not enough space, the homes will also have a separate 700-square-foot two-bed, one-bath unit. Looking to take advantage of the California sunshine? The backyard will feature a swimming pool and deck, but this outdoor space can be upgraded with hot tubs, firepits, or open-air showers...

The homes will be "zero-net-energy," relying on solar and optional Tesla Powerwall batteries for power. Electric vehicle chargers also come optional.
This development should be completed next spring, reports Business Insider — adding that the company "is already in talks with a 'number of developers' for potential future communities."

"A company says it has listed the first 3D printed house in the United States for sale," reports CNN. "This is the future, there is no doubt about it," says Kirk Andersen, the director of operations at SQ4D Inc.

SQ4D uses automated building methods, or 3D printing, to build structures and homes... The company can set up its Autonomous Robotic Construction System at a build site in six to eight hours. It then lays concrete layer by layer, creating footing, the foundation of a house and the interior and exterior walls of the structure... "The cost of construction is 50% cheaper than the cost of comparable newly-constructed homes in Riverhead, New York, and 10 times faster," said Stephen King, the Zillow Premier agent who has the 3D house listing...

"I want people to not be afraid of automation...it is just a different tool and different method. But it's still the same product; we are still building a house at the end of the day," says Kirk Andersen, the director of operations at SQ4D...

"We can make things more affordable and safer. We can use the technology to tackle homelessness, and aid in disaster relief in an eco-friendly way," Andersen said.

Another service is joining the Google graveyard, for better or worse. As the latest in a long series of Google service shutdowns, Cloud Print will be terminated in just a few short hours, meaning it will no longer be accessible for ChromeOS customers or others. From a report: Most internet users have probably never used Cloud Print a single time -- it was primarily designed for ChromeOS customers who had limited or no access to traditional printers years ago. However, now that ChromeOS boasts much broader support for printing devices, Cloud Print has effectively become obsolete. It still has a few unique advantages, such as the ability to share your printers with friends, but for the most part, there's no reason for Google to keep it around.

schwit1 shares a report from Phys.Org: Forget glue, screws, heat or other traditional bonding methods. A Cornell University-led collaboration has developed a 3-D printing technique that creates cellular metallic materials by smashing together powder particles at supersonic speed. This form of technology, known as "cold spray," results in mechanically robust, porous structures that are 40% stronger than similar materials made with conventional manufacturing processes. The structures' small size and porosity make them particularly well-suited for building biomedical components, like replacement joints.

The team's paper, "Solid-State Additive Manufacturing of Porous Ti-6Al-4V by Supersonic Impact," published Nov. 9 in Applied Materials Today. "If we make implants with these kind of porous structures, and we insert them in the body, the bone can grow inside these pores and make a biological fixation," Moridi said. "This helps reduce the likelihood of the implant loosening. And this is a big deal. There are lots of revision surgeries that patients have to go through to remove the implant just because it's loose and it causes a lot of pain." Moridi added: "We only focused on titanium alloys and biomedical applications, but the applicability of this process could be beyond that. Essentially, any metallic material that can endure plastic deformation could benefit from this process. And it opens up a lot of opportunities for larger-scale industrial applications, like construction, transportation and energy."

Micron has announced it's shipping 176-layer TLC NAND flash memory to customers, a move that portends larger, faster and even cheaper SSD drives for all. From a report: The company said its 5th-gen 3D NAND memory should put its density about 40 percent higher than its nearest competitors, which are using 128-layer NAND. Micron said read and write latencies are reduced by 35 percent compared to its 96-layer NAND, and by 25 percent compared its 128-layer NAND. Micron isn't the only NAND memory manufacturer that has 176 layers, but it is the first to start volume shipments. The Micron NAND is TLC, or three-bits per cell, and is said to have 33 percent faster transfer rates, as well as a 35 percent improvement in read and write latencies. And because it's TLC NAND instead of QLC, the new memory should offer better drive endurance, too. The 176-layer design comes from stacking two 88-layer stacks together, which isn't a new thing for Micron. You might think that's a trick, but the end result is still the same: far better density for larger drives. Micron said the new 176-layer NAND is about as thick as one-fifth of a sheet of printer paper, and works out to be as thick its previous 64-layer NAND despite having more than twice as many layers. In the end, this will lead to larger SSDs and potentially cheaper ones, too.

fahrbot-bot shares a report from CNN: A team of physicists at a university in the Netherlands have 3D-printed a microscopic version of the USS Voyager, an Intrepid-class starship from Star Trek. The miniature Voyager, which measures 15 micrometers (0.015 millimeters) long, is part of a project researchers at Leiden University conducted to understand how shape affects the motion and interactions of microswimmers.

Microswimmers are small particles that can move through liquid on their own by interacting with their environment through chemical reactions. The platinum coating on the microswimmers reacts to a hydrogen peroxide solution they are placed in, and that propels them through the liquid. "By studying synthetic microswimmers, we would like to understand biological microswimmers," Samia Ouhajji, one of the study's authors, told CNN. "This understanding could aid in developing new drug delivery vehicles; for example, microrobots that swim autonomously and deliver drugs at the desired location in the human body." In their project, the physicists also printed shapes like boats, trimers and helices, with each object's shape affecting their swimming behaviors.

In a new essay at EFF.org, Cory Doctorow re-visits HP's anti-consumer "security updates" that disabled third-party ink cartridges (while missing real vulnerabilities that could actually bypass network firewalls).

Doctorow writes that it was just the beginning: HP's latest gambit challenges the basis of private property itself: a bold scheme! With the HP Instant Ink program, printer owners no longer own their ink cartridges or the ink in them. Instead, HP's customers have to pay a recurring monthly fee based on the number of pages they anticipate printing from month to month; HP mails subscribers cartridges with enough ink to cover their anticipated needs. If you exceed your estimated page-count, HP bills you for every page (if you choose not to pay, your printer refuses to print, even if there's ink in the cartridges). If you don't print all your pages, you can "roll over" a few of those pages to the next month, but you can't bank a year's worth of pages to, say, print out your novel or tax paperwork. Once you hit your maximum number of "banked" pages, HP annihilates any other pages you've paid for (but continues to bill you every month).

Now, you may be thinking, "All right, but at least HP's customers know what they're getting into when they take out one of these subscriptions," but you've underestimated HP's ingenuity. HP takes the position that its offers can be retracted at any time. For example, HP's "Free Ink for Life" subscription plan offered printer owners 15 pages per month as a means of tempting users to try out its ink subscription plan and of picking up some extra revenue in those months when these customers exceeded their 15-page limit. But Free Ink for Life customers got a nasty shock at the end of last month: HP had unilaterally canceled their "free ink for life" plan and replaced it with "a $0.99/month for all eternity or your printer stops working" plan...

For would-be robber-barons, "smart" gadgets are a moral hazard, an irresistible temptation to use those smarts to reconfigure the very nature of private property, such that only companies can truly own things, and the rest of us are mere licensors, whose use of the devices we purchase is bound by the ever-shifting terms and conditions set in distant boardrooms. From Apple to John Deere to GM to Tesla to Medtronic, the legal fiction that you don't own anything is used to force you to arrange your affairs to benefit corporate shareholders at your own expense. And when it comes to "razors and blades" business-model, embedded systems offer techno-dystopian possibilities that no shaving company ever dreamed of: the ability to use law and technology to prevent competitors from offering their own consumables. From coffee pods to juice packets, from kitty litter to light-bulbs, the printer-ink cartridge business-model has inspired many imitators.

HP has come a long way since the 1930s, reinventing itself several times, pioneering personal computers and servers. But the company's latest reinvention as a wallet-siphoning ink grifter is a sad turn indeed, and the only thing worse than HP's decline is the many imitators it has inspired.

Just when we need them the most, with print shops locked down, online schooling in session, and everyone working from home, they fail to step up. From a column: Printers have been my enemy ever since I can remember. My first office job involved an evil printer that suffered daily paper jams. Tasked with fixing it, I suffered frequent burns and paper cuts. It had a door you had to close just so, or it would immediately break again with the dreaded phantom paper jam. It tormented me for months, completely indifferent to my cries. There isn't even any paper in it! More than two decades later, printers haven't improved at all. It feels like printer companies stopped innovating sometime in the '90s when sales stopped climbing. In fact, it's almost as if they've regressed. Manufacturers tempt with unbelievably cheap deals on printers and then nail you on expensive ink. To make sure they get their pound of flesh, they focus an inordinate effort on making sure printers only work with proprietary ink cartridges.

[...] Three years and a couple of printers later, sick of being gouged for ink cartridges that always seem to run out at the worst moment, I optimistically signed up for a printing subscription plan. The idea is you are charged a flat fee based on how many pages you print each month, and the printer automatically orders ink refills when it's running low. Reading this back, I can only cringe at my naivety. Things were fine for the first few weeks. Then I made the mistake of turning the printer off. It doesn't like to be turned off. It started emailing me, insisting that it needs to be turned on and connected to the internet so the subscription plan can work properly. Every time I turn it on, it prints an ink-heavy test page. It is incredibly good at printing test pages -- it just won't print the document you want. Things got worse when I made the mistake of changing my internet service provider. I forgot about the printer for a while. Then I suddenly needed it. I didn't have time to set up the Wi-Fi, so I plugged directly into the printer with a good old-fashioned cable. It refused to print. I refused to connect it to the internet, so it refused to print for me. To get it working again I had to completely uninstall everything related to the printer, update my drivers, install three separate programs, carry it to another room to plug directly into my desktop, carry it back again, hold down the correct button sequence at the stroke of midnight, spin around three times, and recite the printer incantation into a mirror. It's finally connected and working ... for now. But I know it's only a matter of time before it betrays me again.

A shared user account used by WeWork employees to access printer settings and print jobs had an incredibly simple password -- so simple that a customer guessed it. From a report: Jake Elsley, who works at a WeWork in London, said he found the user account after a WeWork employee at his location mistakenly left the account logged in. WeWork customers like Elsley normally have an assigned seven-digit username and a four-digit passcode used for printing documents at WeWork locations. But the username for the account used by WeWork employees was just four-digits: "9999". Elsley told TechCrunch that he guessed the password because it was the same as the username. ("9999" is ranked as one of the most common passwords in use today, making it highly insecure.)

The "9999" account is used by and shared among WeWork community managers, who oversee day-to-day operations at each location, to print documents for visitors who don't have accounts to print on their own. The account cannot be used to access print jobs sent to other customer accounts. Elsley said that the "9999" account could not see the contents of documents beyond file names, but that logging in to the WeWork printing web portal could allow him to release other people's pending print jobs sent to the "9999" account to any other WeWork printer on the network.

An anonymous reader quotes a report from IEEE Spectrum: New circuits can get printed directly on human skin to help monitor vital signs, a new study finds. In the new study, researchers developed a way to sinter nanoparticles of silver at room temperature. The key behind this advance is a so-called a sintering aid layer, consisting of a biodegradable polymer paste and additives such as titanium dioxide or calcium carbonate. Positive electrical charges in the sintering aid layer neutralized the negative electrical charges the silver nanoparticles could accumulate from other compounds in their ink. This meant it took less energy for the silver nanoparticles printed on top of the sintering aid layer to come together, says study senior author Huanyu Cheng, a mechanical engineer at Pennsylvania State University.

The sintering aid layer also created a smooth base for circuits printed on top of it. This in turn improved the performance of these circuits in the face of bending, folding, twisting and wrinkling. In experiments, the scientists placed the silver nanoparticle circuit designs and the sintering aid layer onto a wooden stamp, which they pressed onto the back of a human hand. They next used a hair dryer set to cool to evaporate the solvent in the ink. A hot shower could easily remove these circuits without damaging the underlying skin. After the circuits sintered, they could help the researchers measure body temperature, skin moisture, blood oxygen, heart rate, respiration rate, blood pressure and bodily electrical signals such as electrocardiogram (ECG or EKG) readings. The data from these sensors were comparable to or better than those measured using conventional commercial sensors that were simply stuck onto the skin, Cheng says. The findings have been published in the journal Applied Materials & Interfaces.

The official public repository for CUPS, an Apple open-source project widely used for printing on Linux, is all-but dormant since the lead developer left Apple at the end of 2019. From a report: Apple adopted CUPS for Mac OS X in 2002, and hired its author Michael Sweet in 2007, with Cupertino also acquiring the CUPS source code. Sweet continued to work on printing technology at Apple, including CUPS, until December 2019 when he left to start a new company. Asked at the time about the future of CUPS, he said: "CUPS is still owned and maintained by Apple. There are two other engineers still in the printing team that are responsible for CUPS development, and it will continue to have new bug fix releases (at least) for the foreseeable future." Despite this statement, Linux watcher Michael Larabel noted earlier this week that "the open-source CUPS code-base is now at a stand-still. There was just one commit to the CUPS Git repository for all of 2020." This contrasts with 355 commits in 2019, when Sweet still worked at Apple, and 348 the previous year. We asked Apple about its plans for CUPS and have yet to hear back.

What happens when we return items to Amazon? "Perfectly good items are being liquidated by the truckload — and even destroyed or sent to landfill," according to Marketplace, an investigative consumer program on Canada's public TV: Experts say hundreds of thousands of returns don't end up back on the e-commerce giant's website for resale, as customers might think. Marketplace journalists posing as potential new clients went undercover for a tour at a Toronto e-waste recycling and product destruction facility with hidden cameras. During that meeting, a representative revealed they get "tons and tons of Amazon returns," and that every week their facility breaks apart and shreds at least one tractor-trailer load of Amazon returns, sometimes even up to three to five truckloads...

To further investigate where all those online returns end up, Marketplace purchased a dozen products off Amazon's website — a faux leather backpack, overalls, a printer, coffee maker, a small tent, children's toys and a few other household items — and sent each back to Amazon just as they were received but with a GPS tracker hidden inside... Of the 12 items returned, it appears only four were resold by Amazon to new customers at the time this story was published. Months on from the investigation, some returns were still in Amazon warehouses or in transit, while a few travelled to some unexpected destinations, including a backpack that Amazon sent to landfill...

Marketplace asked Amazon what percentage of its returns are sent to landfill, recycling or for destruction. The company wouldn't answer. A television investigation in France exposed that hundreds of thousands of products — both returns and overstock — are being thrown out by Amazon. As a result of public outcry, a new French anti-waste law passed earlier this year will force all retailers including e-giants like Amazon to recycle or donate all returned or unused merchandise. Shortly after the show aired in 2019, Amazon also introduced a new program in the U.S. and U.K. known as Fulfillment by Amazon Donations, which Amazon says will help sellers send returns directly to charities instead of disposing of them. No such program exists in Canada.

"Imagine a world where wireless devices are as small as a grain of salt," writes futurist Bernard Marr in Forbes, describing a technology being researched by companies like IBM, General Electric, and Cisco. "These miniaturized devices have sensors, cameras and communication mechanisms to transmit the data they collect back to a base in order to process.

"Today, you no longer have to imagine it: microelectromechanical systems (MEMS), often called motes, are real and they very well could be coming to a neighborhood near you. Whether this fact excites or strikes fear in you it's good to know what it's all about." Outfitted with miniature sensors, MEMS can detect everything from light to vibrations to temperature. With an incredible amount of power packed into its small size, MEMS combine sensing, an autonomous power supply, computing and wireless communication in a space that is typically only a few millimeters in volume. With such a small size, these devices can stay suspended in an environment just like a particle of dust. They can:

- Collect data including acceleration, stress, pressure, humidity, sound and more from sensors

- Process the data with what amounts to an onboard computer system

- Store the data in memory

- Wirelessly communicate the data to the cloud, a base or other MEMs

Since the components that make up these devices are 3D printed as one piece on a commercially available 3D printer, an incredible amount of complexity can be handled and some previous manufacturing barriers that restricted how small you can make things were overcome. The optical lenses that are created for these miniaturized sensors can achieve the finest quality images.

The potential of smart dust to collect information about any environment in incredible detail could impact plenty of things in a variety of industries from safety to compliance to productivity. It's like multiplying the internet of things technology millions or billions of times over.

An anonymous reader quotes a report from Phys.Org: Solar cells can now be made so thin, light and flexible that they can rest on a soap bubble. The new cells, which efficiently capture energy from light, could offer an alternative way to power novel electronic devices, such as medical skin patches, where conventional energy sources are unsuitable. Until now, ultrathin organic solar cells were typically made by spin-coating or thermal evaporation, which are not scalable and which limit device geometry. This technique involved using a transparent and conductive, but brittle and inflexible, material called indium tin oxide (ITO) as an electrode. To overcome these limitations, the team applied inkjet printing. "We formulated functional inks for each the layer of the solar cell architecture," says Daniel Corzo, a Ph.D. student in Baran's team.

Instead of ITO, the team printed a transparent, flexible, conductive polymer called PEDOT:PSS, or poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. The electrode layers sandwiched a light-capturing organic photovoltaic material. The whole device could be sealed within parylene, a flexible, waterproof, biocompatible protective coating. [...] After optimizing the ink composition for each layer of the device, the solar cells were printed onto glass to test their performance. They achieved a power conversion efficiency (PCE) of 4.73 percent, beating the previous record of 4.1 percent for a fully printed cell. For the first time, the team also showed that they could print a cell onto an ultrathin flexible substrate, reaching a PCE of 3.6 percent. The research has been published in the journal Advanced Materials Technologies.