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An engineer’s dinner-table invention is finally a consumer product

For Evan Schneider, the family dinner table is a good place for invention. “I’m always, ‘Wouldn’t it be cool if this or that,’” he says, “and people would humor me.”

In 2012, with California in the midst of a severe drought, Schneider, then a mechanical engineering graduate student at Stanford University, once again tossed out a “cool idea.” He imagined a showerhead that would sense when the person showering moved out from under the stream of water. The showerhead would then automatically turn the water off, turning it back on again when the person moved back into range. With such a device, he thought, people could enjoy a long shower without wasting water.

“But turning the water on and off manually didn’t make sense in our house,” Schneider said. “We had separate knobs for hot and cold, and another one to switch from tub to shower, so you’d have to adjust the water every time you turned it back on. You’d waste more water than you saved. Plus a shower is a blissful time of relaxation. You don’t want to stop the party halfway.”

Ten years and many starts and stops later, that sensing showerhead is now shipping to customers from Oasense, a company incorporated in 2019.

“The general idea is really simple,” Schneider says. “A lot of people have said they also thought of this idea. And I’m sure that’s true, but there were a lot of devils in the details.” Oasense’s team has been granted several patents related to their device, the first filed by Schneider in 2016.

Schneider’s development path started soon after that dinner-table conversation. First, he confirmed that showers were a big part of water usage for a typical household, and that no such device was already on the market. He collected off-the-shelf components, including an infrared sensor scavenged from a high-end automatic faucet, designed a prototype in a CAD system, printed out the plastic parts using a 3D printer, and assembled it. With 4 AA batteries as a power source, the gadget would operate for about a year, thanks to his choice of a latching solenoid valve, one that uses power to switch from open to closed but doesn’t draw any power to hold in one state or another.

The prototype worked well enough that his parents were willing to throw out their standard showerhead. He assembled dozens of them and distributed them to friends and family—anyone willing to try.

Oasense cofounder Ted Li assembles an early version of the company’s sensing showerhead.Oasense

In 2016, Schneider decided to run a Kickstarter campaign to see if the gadget could attract broad interest. The Kickstarter ultimately failed; it drew a decent number of potential buyers, but, says Schneider, “I had set the bar high, because I was busy doing other things, and if I switched to this, I wanted to make sure it would have a good chance of working out. It didn’t meet that bar; it raised about US $34,000 out of its $75,000 goal.”

So Schneider put his showerhead idea on hold. Instead, he focused on expanding a burgeoning small business that he was also passionate about—3D printing prototypes and various parts for hardware companies.

But the showerhead wasn’t done with him. In 2017 someone who Schneider had never met edited the video from the Kickstarter pitch and shared it on Facebook. This time, the video got far more attention—millions of views in just weeks.

Unfortunately, the timing couldn’t have been worse. Schneider was dealing with a flare-up of a chronic illness and his 3D printing business was at a critical growth period. “I had wanted this for years, but it was the worst time for it to happen,” he says.

“I still believed in the product,” Schneider continued, “but I knew it needed improvements and more attention than I was able to give it. I tried for a couple of weeks to reply to all these people contacting me, thousands of them, but it was too much. I was planning to shelve it.”

That’s when Chih-Wei Tang, a friend from Stanford’s mechatronics program who had been an early backer of the project on Kickstarter, reached out to Schneider. Tang, who was working as a technical product manager at the Ford Greenfield Labs, convinced Schneider that he could form a team capable of commercializing the product. Tang pulled in his friend Ted Li, who had just left Apple after managing display technology for the iPhone and Apple Watch.

Tang and Li devoted themselves to the project full-time, Schneider helped part-time as needed. The three started by trying to better adapt an off-the-shelf sensor, but ended up designing a sensor suite with custom hardware and algorithms.

They incorporated as Oasense in December 2019 as cofounders. In late 2020, the company went out for funding, and brought in about $1 million from angel investors, friends, and family. In addition to the founders, Oasense now has four full-time and three part-time employees.

Oasense cofounders [from left] Ted Li, Evan Schneider, and Chih-Wei Tang.Oasense

The current version of the device includes several sensors (across a wide range of light wavelengths) and software that allows the sensors to self-calibrate, since every shower environment is different in terms of light, reflectivity, size, and design. Calibration happens during warm-up, when the person showering is unlikely to be standing in the stream. A temperature sensor determines when this warm-up period is over and cuts the flow if the user hasn’t moved under the showerhead. The redesign also replaced the AA batteries with a turbine that generates power from the water flow and sends it to a small rechargeable battery sealed inside the device.

Says Tang, “It does seem like someone would have built this before, but it turns out to be really complicated. For example, one problem that affects the noise in the sensor signals is fog. In a hot shower, after 3 minutes, our original sensor was blinded by fog. When we designed our new sensors, we had to make sure that didn’t happen.

“And these sensors are power hungry and need to be on for the duration of the shower, whether water is flowing or not, so generator and sensor efficiency had to be maximized.”

Oasense officially launched its product, Reva, in August. The company is working to figure out the best way to sell the gadget; it is now just doing direct sales at $350 per self-installable unit.

“Two trends are coming together,” Tang says. “Sustainability is what everyone has to be about these days, and technology is invading every corner of our homes. Using technology, we designed sustainability into a product that doesn’t compromise quality or the experience, it just addresses the problem.”

Tekla S. Perry is a senior editor at IEEE Spectrum. Based in Palo Alto, Calif., she's been covering the people, companies, and technology that make Silicon Valley a special place for more than 40 years. An IEEE member, she holds a bachelor's degree in journalism from Michigan State University.

I’ve been using this shower head for months and have saved a lot of water. I’m glad to see it getting more exposure.

Formerly rival technologies have come together in Samsung displays

Sony's A95K televisions incorporate Samsung's new QD-OLED display technology.

All these products use display panels manufactured by Samsung but have their own unique display assembly, operating system, and electronics.

I took apart a 55-inch Samsung S95B to learn just how these new displays are put together (destroying it in the process). I found an extremely thin OLED backplane that generates blue light with an equally thin QD color-converting structure that completes the optical stack. I used a UV light source, a microscope, and a spectrometer to learn a lot about how these displays work.

Samsung used a unique pixel pattern in its new QD-OLED displays.

As for the name of this technology, Samsung has used the branding OLED, QD Display, and QD-OLED, while Sony is just using OLED. Alienware uses QD-OLED to describe the new tech (as do most in the display industry).

For more than a decade now, OLED (organic light-emitting diode) displays have set the bar for screen quality, albeit at a price. That’s because they produce deep blacks, offer wide viewing angles, and have a broad color range. Meanwhile, QD (quantum dot) technologies have done a lot to improve the color purity and brightness of the more wallet-friendly LCD TVs.

In 2022, these two rival technologies will merge. The name of the resulting hybrid is still evolving, but QD-OLED seems to make sense, so I’ll use it here, although Samsung has begun to call its version of the technology QD Display.

To understand why this combination is so appealing, you have to know the basic principles behind each of these approaches to displaying a moving image.

In an LCD TV, the LED backlight, or at least a big section of it, is on all at once. The picture is created by filtering this light at the many individual pixels. Unfortunately, that filtering process isn’t perfect, and in areas that should appear black some light gets through.

In OLED displays, the red, green, and blue diodes that comprise each pixel emit light and are turned on only when they are needed. So black pixels appear truly black, while bright pixels can be run at full power, allowing unsurpassed levels of contrast.

But there’s a drawback. The colored diodes in an OLED TV degrade over time, causing what’s called “burn-in.” And with these changes happening at different rates for the red, green, and blue diodes, the degradation affects the overall ability of a display to reproduce colors accurately as it ages and also causes “ghost” images to appear where static content is frequently displayed.

Adding QDs into the mix shifts this equation. Quantum dots—nanoparticles of semiconductor material—absorb photons and then use that energy to emit light of a different wavelength. In a QD-OLED display, all the diodes emit blue light. To get red and green, the appropriate diodes are covered with red or green QDs. The result is a paper-thin display with a broad range of colors that remain accurate over time. These screens also have excellent black levels, wide viewing angles, and improved power efficiency over both OLED and LCD displays.

Samsung is the driving force behind the technology, having sunk billions into retrofitting an LCD fab in Tangjeong, South Korea, for making QD-OLED displays While other companies have published articles and demonstrated similar approaches, only

Samsung has committed to manufacturing these displays, which makes sense because it holds all of the required technology in house. Having both the OLED fab and QD expertise under one roof gives Samsung a big leg up on other QD-display manufacturers.,

Samsung first announced QD-OLED plans in 2019, then pushed out the release date a few times. It now seems likely that we will see public demos in early 2022 followed by commercial products later in the year, once the company has geared up for high-volume production. At this point, Samsung can produce a maximum of 30,000 QD-OLED panels a month; these will be used in its own products. In the grand scheme of things, that’s not that much.

Unfortunately, as with any new display technology, there are challenges associated with development and commercialization.

For one, patterning the quantum-dot layers and protecting them is complicated. Unlike QD-enabled LCD displays (commonly referred to as QLED) where red and green QDs are dispersed uniformly in a polymer film, QD-OLED requires the QD layers to be patterned and aligned with the OLEDs behind them. And that’s tricky to do. Samsung is expected to employ inkjet printing, an approach that reduces the waste of QD material.

Another issue is the leakage of blue light through the red and green QD layers. Leakage of only a few percent would have a significant effect on the viewing experience, resulting in washed-out colors. If the red and green QD layers don’t do a good job absorbing all of the blue light impinging on them, an additional blue-blocking layer would be required on top, adding to the cost and complexity.

Another challenge is that blue OLEDs degrade faster than red or green ones do. With all three colors relying on blue OLEDs in a QD-OLED design, this degradation isn’t expected to cause as severe color shifts as with traditional OLED displays, but it does decrease brightness over the life of the display.

Today, OLED TVs are typically the most expensive option on retail shelves. And while the process for making QD-OLED simplifies the OLED layer somewhat (because you need only blue diodes), it does not make the display any less expensive. In fact, due to the large number of quantum dots used, the patterning steps, and the special filtering required, QD-OLED displays are likely to be more expensive than traditional OLED ones—and way more expensive than LCD TVs with quantum-dot color purification. Early adopters may pay about US $5,000 for the first QD-OLED displays when they begin selling later this year. Those buyers will no doubt complain about the prices—while enjoying a viewing experience far better than anything they’ve had before.