How Touch-Tech Faucets Work

How Touch-Tech Faucets Work

Delta Faucet asked us to do something with them and their touch-faucet technology. Of course, our first thought was: Tell us how it works. We interviewed Bob Rodenbeck, director of research and development, and here’s some of what he had to say. -Gareth

Make: Can you first give us an overview of the faucet itself? Is this the first of its kind?

Bob Rodenbeck: For more than 10 years, Delta Faucet Company has been researching and designing touch and hands-free faucet technologies. The company introduced its first electronic kitchen faucet in 2005, on the Brizo brand Pascal culinary faucet, which launched in 2006 with a combination of touch-activated and hands-free sensing.

In 2008, we introduced the first touch-activated faucet under the Delta brand (Delta Pilar pull-down kitchen faucet with Touch2O® Technology) and have since continued to expand from there. In 2011, Delta Faucet introduced Touch2O® and Touch2O.xt™ Technology (touch and hands-free) to the home bathroom. Besides convenience, electronic faucets also help reduce the transfer of messes from the hands to the faucet.

Make:Can you give us an overview of the faucets and the tech?

Bob Rodenbeck:Our Touch2O and Touch2O.xt technology were born of ethnographic research and human behavior studies to satisfy an unmet need of turning on a faucet with messy hands and turn off the water when it’s not needed between tasks.

One of the interesting things we found during our research of consumers is that while the idea of hands-free technology resonates with them, they prefer the control and responsiveness of our touch technology in the kitchen. So much activity happens in and around the kitchen sink that hands-free sensing can activate water when it really wasn’t needed. We call those surprise activations.

MAKE: How does the touch technology actually work? (We have a fairly sophisticated audience, so don’t be afraid to be technical)

Bob Rodenbeck: Every person has a characteristic called capacitance. Capacitance is an electronic value measure in farads. Capacitors store electrical energy. A human body typically has 22 picoFarads of capacitance. A result of this capacitance is often felt in the winter months, via static discharges that occur when walking across a carpet and touching a metallic object. Walking across a carpet generates energy that is stored in the body’s capacitance. This energy is discharged when touching another object at a different voltage potential.

A capacitive touch sensor is basically a sensing device that measures capacitance in its environment. When a touch sensor is connected to the faucet, it first establishes a baseline level of capacitance. Once this is established, it then looks for an increase in capacitance that occurs when a person touches the faucet (the human body’s 22 pF). The sensor detects the increase and either turns on water flow or turns off water flow. When the person releases the faucet, the decrease in capacitance is also detected.

Touches and grabs are distinguished by measuring the duration of the person touching the faucet. Touches are defined as being less than 300 milliseconds, and grabs as more than 300 milliseconds.

There are two capacitive touch sensors in the faucet. The first sensor is connected to the handle and the second is connected to the spout. If a touch sensor is connected to anything conductive (wire, metal sheet, metal bar, etc.) that conductive element becomes an extension of the touch sensor.

The first sensor is attached to the handle which is made of brass. Since brass is conductive, the entire handle of the faucet is a touch sensor. The second capacitive sensor is connected to the spout. As the spout is also made of brass, it is also a touch sensor.

MAKE: Are there technical challenges to this type of sensing?

Bob Rodenbeck: The technical challenges we faced were isolated to a few areas: adding electronics to the faucet without taking away from the aesthetics, identifying and sourcing the right materials to ensure the technology worked as it should across a wide range of faucet styles and installations (sink material and type, water quality, installer variability, etc..), and determining the precise sensitivity to ensure the functionality was intuitive and convenient to the end user.

Our biggest challenge with this technology really had nothing to do with the technology itself and more with the mindset of users. There are certain perceptions or opinions about electronic faucets – mostly based on past experiences – we needed to overcome. By far, the largest challenge of incorporating capacitive technology into faucets was changing the perceptions and habits of faucet installers. In the case of Touch2O, the installation isn’t itself that hard, but it is different from a traditional faucet installation.

A key technical challenge involved ensuring the faucet is properly isolated from any surrounding metal (i.e. sinks) and ensuring that water (inside and outside the faucet) doesn’t affect the performance of Touch2O Technology.

MAKE: What are some of the positive benefits of this sort of technology? Disadvantages?
Bob Rodenbeck: Touch2O Technology is amazingly intuitive and extremely responsive to the user, resulting in economies of motion and ease of use. Touch2O Technology and Touch2O.xt Technology make it easier to turn on the water flow when hands are messy or turn off the water when it is not needed between tasks, potentially saving water. It also helps keep the faucet cleaner while helping to reduce the potential for cross-contamination.

The only disadvantage we’ve noticed so far is that these faucets are still relatively new and as with all new technologies and innovation platforms, there’s a certain learning curve. We’re still working to change attitudes toward electronic faucets and also address hesitations about the idea of mixing electricity and water. In reality, the technology operates on batteries and uses the energy stored in our own bodies to activate the faucet.

MAKE: Where are some of the places you see this type of technology going?
Bob Rodenbeck: There is a lot of research, collaboration and testing that comes into play when the research and development team is working on launching a new product. The R&D, design and engineering team all work together throughout the process because we believe that the collaboration results in creating better products for our consumers.

You can find touch technology almost everywhere now and continues to expand into new applications. Touch functionality is on phones, computers and other tech gadgets. But, it isn’t something you expect to see on a kitchen or bathroom faucet. Our research and development team is always looking for new applications of the technology as we aim to provide people with a better way to work with water.

21 thoughts on “How Touch-Tech Faucets Work

  1. Crazzy Cool says:

    That’s great idea to bring it to kitchen. So much easier to turn on the tap without touching it with the dirty hands. Normally you can see this technology in washrooms. Is that the same technology you are using? or different?

    1. ameyring says:

      As far as I’ve seen, automatic faucets and toilets in public washrooms activated by an infrared light beam bouncing off your body back into the appliance’s detector. You can tell this when you wear something very dark and the light beam is absorbed, not triggering the appliance.

      1. simone says:

        Even better, there are some faucets activated by pedals.
        Really hands free, and you can adjust the flow like a normal tap, but using your feet.

  2. miroslava von schlochbaum says:

    Two things that would’ve been nice to include about these things would’ve been:
    how much electrical energy over a typical week’s use does this require?
    how often are they falsely triggered? (that is, it never happens that a near lightening storm turns on all your facets… or a cockroach running over them … yes?)

  3. kurtroedeger says:

    I’d be interested to know if it has a timed shut-off feature. My cats already rub across my faucets when they want me to turn it on for them to drink. If they figure out they don’t need me, the faucet would run the entire day while I’m at work.

    1. Eric says:

      The kitchen faucet has a 4 minute automatic shut-off. Touch20.xt in the bath has a 1 minute automatic shut-off… Teach the cats to use the bathroom faucet; it’ll save water ;)

  4. RHMathis says:

    I’ve already run into radio interference from touch table lamps (both inward and outbound), since I’m a half-century ham radio operator and EE. What is the approximate frequency generated by the technology? And what about nearby strong RF fields and triggering problems?

    1. H Leck says:

      I have the same questions. No more RFI generating electronics!

      1. RHMathis says:

        I notice no replies to my comment about RFI OUTPUT or RF triggering of the faucets in homes owned by amateur radio enthusiasts. Perhaps this article is not set up for the author to be notified when there are comments. Maybe someone at the Make: site could see that he sees this comment stream?

  5. MAKE | The Science of the Shower says:

    […] in May we published a post about Delta Faucet’s Touch technology. It was pretty interesting stuff for something many of […]

  6. The Science of the Shower says:

    […] in May we published a post about Delta Faucet’s Touch technology. It was pretty interesting stuff for something many of us […]

  7. Wendy says:

    We have one of these kitchen faucets and purchased it as soon as it was available in 2005. It is by far one of the “coolest” products we purchased for our new home and all of our kid’s friends (and some of ours!) love the way it works! We have absolutely loved it…until today…it is suddenly not working. Fortunately, the water still flows, but the touch/hands free portionis not. It appears to be an electrical problem. We are worried that, one:there isn’t anyone who will know how to fix it, and two: there is no fix. As it was a fairly expensive faucet, we hope it is neither of these! Anyone have any suggestions?..

  8. Comparing Touch and Touch-free Faucets | Touchless Faucets | | The Faucet Expert says:

    […] any style. Delta Faucet introduced the first touch faucet for residential consumers in 2008. Bob Rodenbeck, Delta’s director of R & D, explained to Make magazine how the touch technolog….In a nutshell, human beings have capacitance, which is how the body stores electrical energy. Delta […]

  9. Rob Stone says:

    Can someone please help me with my faucet. Delta support has been no help. Replacing the faucet has not worked. I have a very strange problem. Touching the faucet handle works but touching the faucet neck does not. None of the troubleshooting steps have led to why this is.

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  11. Gathee Mukiri says:

    I have always been fascinated by touch technology, but would love if you developed a thorough articles as this one on touch less faucets . I have seen in a previous post people claiming that the faucet is discriminating against them…what could really be the issue?

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Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and “lazy man’s memoir,” called Borg Like Me.

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