This Idea Wasn’t All Wet: The Water-Sensing Sensor-Saving Shower Head Makes Its Debut

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

In 2012, when California was in the midst of a severe drought, Schneider, then a graduate student in mechanical engineering at Stanford University, once again pitched a “good idea.” He imagined a showerhead that would detect when the person taking the shower would step out from under the stream of water. The showerhead would then automatically turn off the water and turn it back on when the person comes 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 buttons for hot and cold, and another to switch between bath and shower, so you had to adjust the water every time you turned it on. You will waste more water than you save. Plus, a shower is a nice relaxing time, you don’t want to stop the party halfway.

Ten years and many starts and stops later, this sensor-sensing showerhead is now shipping to customers of Oasense, a company incorporated in 2019.

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

Schneider’s development journey began shortly after that conversation at the dinner table. First, he confirmed that showers make up a large part of a typical household’s water consumption and that no such device was already on the market. He gathered ready-to-use components, including an infrared sensor salvaged from a high-end automatic faucet, designed a prototype in a CAD system, printed the plastic parts using a 3D printer, and assembled it. With 4 AA batteries as a power source, the gadget would run for about a year, thanks to its choice of a latching solenoid valve, a solenoid valve that uses power to switch from open to closed but consumes no power to stay in one state or another.

The prototype worked well enough that his parents were ready to throw away their standard showerhead. He collected dozens of them and distributed them to his friends and family, to anyone who was willing to try.

Oasense co-founder Ted Li assembles an early version of the company’s sensor-sensing showerhead.oasense

In 2016, Schneider decided to launch a Kickstarter campaign to see if the gadget could generate widespread interest. The Kickstarter ultimately failed; it attracted 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 moved on, I wanted to make sure that he would have a good chance of running out.He didn’t hit that mark, he raised about $34,000 of his $75,000 goal.

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

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

Unfortunately, the timing couldn’t have been worse. Schneider was dealing with a flare-up of chronic illness and his 3D printing business was in a period of critical growth. “I’ve wanted it 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 could give it. I tried for a few weeks to respond to all these people who contacted me, thousands of them, but it was too much, I intended to put it aside.

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

Tang and Li dedicated themselves to the project full-time, Schneider helping out part-time as needed. The three started out trying to better fit a standard sensor, but ended up designing a suite of sensors with custom hardware and algorithms.

They incorporated as Oasense in December 2019 as co-founders. At the end of 2020, the company applied for funding and brought in approximately $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 co-founders [from left] Ted Li, Evan Schneider and Chih-Wei Tang.oasense

The current version of the device includes multiple sensors (over 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, in size and design. Calibration happens during warm-up, when the person showering is probably not in the stream. A temperature sensor determines the end of this warm-up period and cuts off the flow if the user has not moved under the showerhead. The redesign also replaced AA batteries with a turbine that generates power from the flow of water and sends it to a small rechargeable battery sealed inside the device.

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

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

Oasense officially launched its product, Reva, in August. The company is struggling to find the best way to sell the gadget; it now only does direct sales at $350 per self-installing unit.

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