Keep Clean Correctly

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With the Sars-Cov-2 virus circulating the world, we have all heard these simple instructions from organizations like the CDC and the WHO: "Wash your hands for at least 20 seconds.” Even when there isn't a pandemic, many people die due to improper hand washing. According to the CDC (1) "about 1.8 million children under the age of 5 die each year from diarrheal diseases and pneumonia," and that "handwashing with soap could protect about 1 out of every 3 young children who get sick with diarrhea and almost 1 out of 5 young children with respiratory infections like pneumonia." Even though these instructions are simple, they are often overlooked and disregarded.

The Problem

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So What?

Many people incorrectly assume that 20 seconds is just a random amount of time for how long to wash their hands. Many studies have been conducted on this topic and many countries and organization have reached a consensus that one must wash for at least 20 seconds. (2) On the left you can see an experiment that uses a lotion that mimics viruses and glows under ultraviolet light (3). Soap molecules have one side that attracts to viruses and the other side to water. Washing for less than twenty seconds doesn't provide the soap sufficient time to bond to the virus and rip it apart


The Solution

The child mode is the default as children are more likely to disregard the twenty second rule. The child mode is triggered by simply placing one's hand into the soap dispenser. In this mode, the LEDs light up in a rainbow of colors and music is played through the speakers.


For adults, who may not enjoy rainbow flashing colors, we have created a mode with a mellower array of colors. To enable this mode, one simply has to press a button. The button is conveniently placed on the wall next to where the soap is dispensed, so it can easily be pressed while the soap is being dispensed. This mode disables the music, and the LEDs fade from green to red instead of flashing rainbow colors.

To combat the lack of thoroughness in hand washing, we have designed an automatic soap dispenser with a built in countdown, so the user is actively told how long to wash their hands. The countdown is displayed through an LED strip placed under the soap to make it glow. We have also built into the dispenser, two different modes, one for children and the other for adults. While a single mode would accomplish the goal, having two specified mode creates a better experience for all users.


Parts List

Total Cost to Build ~ $17

Hover over pictures for more details 

The Arduino is the brains of the product. In this project it reads information from the distance sensor and holds the code for the LED strip and music.

Quantity: 1

Price: $5

Arduino Uno

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The WS2812b LED strip is a special LED strip that allows us to control each LED individually and create unique color schemes to be displayed.

Quantity: 1

Price: $3.50


WS2812b LED Strip

The IR distance sensor is a small and accurate distance sensor that allows us to monitor motion. When the distance being read changes, the arduino understands that means there was movement, and the next action can be triggered.

Quantity: 1

Price: $1.50

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IR Distance Sensor

In this project the button is to give the user input to inform the Arduino if they are an adult or not. When an adult sticks their hand under the distance sensor they can also press the button. The arduino will then use a simple green to red fade instead of a rainbow of colors

Quantity: 1

Price: $1.50 for 25 (6¢ per)

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Arduino Button

The transistor is used to amplify the Arduino's output to the pump and speakers since they require additional power to operate.



Quantity: 2

Price: 10$ for 20 (5¢ per)


P30NO6LE Transistor

The peristaltic pump will pump soap from the container to the top where it will fall onto the user's hand. The use of a pump makes the dispenser automatic and more user friendly.

Quantity: 1

Price: $2.60

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Peristaltic Pump

The speakers allow the dispenser to output audio. With these speakers we play music to appeal to our younger audience while they wash their hands.

Quantity: 2

Price: $1.85 for 2



The resistors are used to limit the current in the device. Without the resistors some of the components would receive too much current and break.

Quantity: 3

Price: $0.50 for 100 (.5¢ per)


The wires are used to connect all the components to the Arduino and transfer data or power to and from the Arduino. 





Quantity: <3ft

Price: $15 for 180 ft. (8¢ per foot) 



Without the tubing the dispenser would have no pathway to move the soap from the base to the dispenser hole. The tubing provides a simple pathway and keeps the electronic components safe from the soap.

Quantity: 1

Price: $1

Silicon tubing

In order for any electronic device to operate it needs a power source, in our case it is a 9V battery.

Quantity: 1

Price: $1

9V Battery

The prototype is built from cardboard. The base is made from a slightly altered tissue box, and the rest is scrap cardboard. In the future this device will be made from plastic which is more durable.

Quantity: ~ 20 cubic inches

Price: Cardboard - Free (scraps)

        ABS plastic ~ $1

Building Materials



Adult Mode

Child Mode

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Circuit Diagram


System Flowchart

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CAD Model for Future Developments

(Made with fusion360 & adobe illustrator)

Product Developement


The Anti-Bacteriophage

The "C"lean Machine

Refinement with CAD (fusion360)

Our original concept was based on a bacteriophage, a harmful virus. We called it "The Anti-Bacteriopahge" since its goal was to kill the virus. After making this design we realized this design wasn't very functional, even though it looked great. It would be top-heavy, take up a lot of space, and only appeal to a  small demographic.

The second design was a more practical design, a "C" shape, with a thick base. This design works well since the base gets filled with soap stabilizing the device and the top of the "C" is a convenient place to put the motion sensor and dispense the soap from.

Our design for the future is a refinement of our prototype. Corners are rounded to be more aesthetically pleasing and seeing the amount of remaining soap is easier with the clear wall. This design can also hold more soap than the prototype.





Arduino Code






The first section of the code is the integers & libraries. Here there are three subdivisions , the stuff for the distance sensor, stuff for the LEDs and all the other integers.

The second section is the setup. The Arduino is told how it will be using each pin and the serial monitor is initiated. The serial monitor gives us the ability to see the distance being read by the distance sensor and it helps debug other parts of the code.

In the void loop, we are checking to see if the distance being read has changed. If it has changed then the pump will pump soap for the set amount of time. Then the Arduino will set an integer equal to whatever millis() is so it can calculate when 20 seconds from the start of the lights will be. After this the Arduino checks to see if the button for adult mode was pressed. If it wasn't pressed the child mode function is called, but if it was pressed then the adult mode function is called.

The first part of the child mode is the while statement which checks to see if the set amount of time has passed, and if the adult mode button has been pressed. The addition of the second requirement allows the user to change the mode to adult mode even after the child mode has started. After that three values are set randomly to be RGB values for the LED strip and then  displayed for a short amount of time before repeating.

The adult mode starts with the same while statement as the child mode except that the buttonVal is different. In the function a few equations are used to create a fade from green to red. The equations create a unique fade from green to red. On a graph, the equation creates a curve that equals the change from green to red overtime. A regular linear fade made the full intensity red appear too early.

This is the function for the interrupt. It just changes the variable for the mode. e used an interrupt to make sure the arduino will pick up the button press whenever it happens.


Competitors/Existing products


Method Gel Handwash(7)

Price: $3

Target Consumers: This product is for households 

Capacity: 12 oz.

Pros: Cheap, fits on counter tops

Cons: small capacity, manual

Simplehuman Standard Sensor Pump(9)

Price: $50

Target Consumers: This soap dispenser is meant for household consumers.

Capacity: 8 oz.

Pros: Fits on countertops, Hands free

Cons: Expensive, small capacity

PURELL ES8 Dispensing System(8)

Price: $40

Target Consumers: This soap dispenser is well suited for schools and other public domains

Capacity: 40.64 oz.

Pros: Large capacity, battery change with refill, hands free, wall mounted(good for public usage)

Cons: Expensive proprietary refills ($48 for 2 refills), wall mounted (bad for households) 

The global market for electronic soap dispensers was estimated to be 668.3 million USD in 2018. This is expected to increase at a CAGR (compound annual growth rate) of 6.0% from 2019-2025. Within the industry there are three groups of consumers:  residential, institutional, and commercial. Of these categories, the residential sector is expected to grow the fastest at a CAGR of 7%, which is the sector our product, the Clean Machine, is in. (4)

The source of the sector’s expected rapid growth is a result of the rising popularity for “smart” products, the increasing buying power of the middle class in countries such as India and China, and the increase in awareness surrounding hand hygiene. Additionally electronic dispensers are more efficient than their manual counterparts. Electronic dispensers give a specific amount of soap every time they are used, reducing the usage of unnecessary soap and preventing the usage of insufficient amounts of soap. (5)

Around the world, programs initiated by governments have been indirectly boosting the whole industry's growth. As governments promote proper sanitation for water and general hygiene, more people become aware of the importance of being hygienic. Furthermore, the emergence of Covid-19 has accelerated the spread of awareness regarding hand hygiene. The awareness around basic sanitation and hygiene, specifically hand hygiene, is leading to the increase in purchasing of soap dispensers, everywhere. (6)

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The Electronic Soap Dispenser Market

Why You Should Choose The Clean Machine

The Clean Machine was built around the user experience. The LEDs are under the soap, so the soap glows and the color is easy to see. The distance sensor, button and the dispensing hole are placed so that they can all be used at the same time, with just one hand. The C shape hides the dispensing hole and the distance sensor from eye sight, and leaves the button visible so one can easily see and press it. Finally, the large opening on the top of the soap container allows for easy refills.

Not only did we physically design the Clean Machine for functionality, we understand that not everyone will be engaged by the same mode. It would have been much easier to create a single mode to display the 20 second countdown, but we saw an opportunity to create a more successful device by thinking about how to engage different users. One mode is exciting rainbow colors, but we know not everyone will like that, so there is a calmer green to red fade as well.

In a survey we conducted among our peers, the number one reason for improper hand washing was forgetfulness (check out the survey). Nearly 1 in 3 people we surveyed said that when they wash their hands they forget the twenty second rule. Other automatic soap dispensers don’t address this issue at all. On the other hand, we step beyond the soap dispenser itself and help the user improve their hand washing. 

Smart bathroom products are rising in demand across the globe. People want better soap dispensers to help them keep their hands clean. The growth expected to occur in the electronic soap dispenser market makes the Clean Machine more than just a good concept, it becomes one posed to succeed.

Hand Washing feels like an insignificant action. We need to break that mentality. Every year millions of people die from diseases that could have been prevented by proper hand washing. The Clean Machine promotes proper hand washing for anyone who uses it.

User-Centered Design

Built For Everyone

Save Lives

Growing Market

Improves Hand Washing

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FAQ - From Class Discussion and Other Peers

Why not just set a timer?

​There are two answers for this question:

  1. Forgetfulness. In data we collected from our peers, (10)  the number one reason for improper hand washing was forgetfulness. Our dispenser addresses this problem by automatically starting the timer whenever one is washing their hands. If one has forgotten the twenty second rule, the dispenser reminds them when it is used, whereas if one was reliant on a timer, they would forget to use the timer as well.​

  2. Convenience (11). Our goal is to help as many people as possible wash their hands correctly. Convenience is a huge factor in people's acceptance of a solution. By combining the soap dispenser and the timer, we eliminate extra steps. If the solution was to start a timer, many people wouldn't bother to start the timer, but when it is automatic, there is no extra effort required.

Why would someone want to use the adult mode, when the child mode is so much more fun?

If you prefer the child mode go ahead, in fact child mode is the default! When designing the product we took into account that not everyone will have the same preferences so we included separate modes directed at adults and children. But, just because you are an adult doesn't mean you have to use the adult mode. If the mode directed at children enhances your experience more, then you should use it, all you have to do is not press the button.

Doesn't having a button defeat the purpose of having a no touch soap dispenser? 

To activate adult mode, you will have to press a button, but this is not a problem as you are washing your hands right after touching the button. If having a button still concerns you, future iterations will use a brass capacitive button. Copper and its alloys (such as brass) are antimicrobial, which means they have an inherent ability to kill microorganisms and they do it quickly. In places with high levels of harmful microorganisms, like a hospital ICU, the usage of copper or one of its alloys alone can reduce infection rate as much as 58% (12). The antimicrobial button and the fact that after touching the button one's hands are washed, even when the button is touched there will be practically no microorganisms transmitted. The capacitive brass button also has the added benefit of easier usage

Can the flashing lights in the child mode be a problem for those with epilepsy?

In the future we hope to develop an app that will allow the user to monitor the dispenser and personalize it from their mobile device. One can check how much soap is remaining in the dispenser and the battery percentage of the soap dispenser in the app. The personalization feature will allow the user to customize the adult and child modes. The user can change the colors, change if they fade or flash, and the intensity. In the case of an epileptic user, they will have the option to change the modes to more epileptic friendly settings

Still have a question?

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About Us

Our Mentors

Mrs. Rifkie Silverman

Mr. Michael Preston


The Clean Machine Team

From The Frisch School

Eytan Abramowitz

Software & Fabrication Lead

Bayla Neugroschl

Research Coordinator

Gabe Greenfield

Video/Creative Director