How we came about to building the world’s first biodegradable and smart water filter

Developing TAPP2 smart water filter

In this article we will why and how we developed TAPP 2 smart water filter in China in collaboration with Innozen Electronics.

Last year more than 250 billion bottles of water were consumed. This resulted in unsustainable amounts of plastic pollution being dumped into rivers, lakes, and oceans, and making their way back to our taps as microplastics.

How did we get there? Why are people buying bottled water at a premium?

Water is the source of all life on earth. Mountains, rivers, lakes, aquifers used to offer pristine clean water. Water was only tainted in rare cases by naturally occurring toxins, harmful to humans, such as Coliform or Arsenic.

Then came the agricultural and industrial revolutions and we poisoned our most precious resource.

At the same time, governments started introducing water treatments such as chlorine to kill bacteria, all the while filtering technology was improving.

The overall outcome was safe drinking water, despite human pollution.

Unfortunately, chemical treatments combined with aging pipe infrastructure have resulted in a deterioration of taste and odor of running water... This has driven many people to make the switch to bottled water.

How we came about to building the world’s first biodegradable and smart water filter

Where and how to produce the product?

TAPP 2 smart water filter was designed in our research lab in Barcelona Spain, with support from a local industrial design studio, universities and leading water scientists. Once the prototype had been designed and developed it was time to find a production partner.

Initially we considered making TAPP 2 in Europe to have better control and reduce the environmental impact of shipping across the world. However, after speaking to multiple consumer products manufacturers we quickly realised this wouldn't be possible due to sourcing of components, cost and quality concerns.

We narrowed down the best production facilities for water filtration to Shenzhen China (and surrounding region) and Taiwan. Following this we contacted design consultants and manufacturers. After a 3 month selection process we chose to work with Innozen Electronics as our design, sourcing and project management partner in Shenzhen.

The next step was to find the best materials and mass production design based on the prototype.

Biodegradable is the way forward

When thinking about how to design TAPP 2, something was clear: we were not going to build a product which requires the use of disposable plastic pieces. If we are working towards reducing plastic, we couldn’t be producing more disposable plastic. Therefore TAPP 2 was designed with biodegradable refill cartridges. Each refill is made using biodegradable materials which can be disposed of with organic waste.

TAPP2 smart water filter

This, of course, did bring a few challenges. We wanted to offer a competitive faucet water filter. People should not have to pay more for doing the right thing. Equipped with all our learning's from TAPP 1, we met with a team of engineers and designers.

One of the main challenges was to find materials which would be food-grade ready, biodegradable, but slow to biodegrade as they are constantly in contact with water.

Then the second challenge was to find a workaround for using glue. Other filter manufacturers use glue to maintain the carbon block into position. As it turned out though, most glues are non-biodegradable and have a negative impact on the environment, and unfortunately, there are still no biodegradable glues which can withstand such prolonged contact with water. We found a mechanical solution, compressing the carbon bloc between two bioplastic pads to ensure the carbon block is properly fastened into position.

That last challenge was actually a major one, and we have been struggling to find the appropriate bioplastic, with FDA approval. Together with Innozen Electronics we decided to temporarily use silicon, which is non-toxic, inert and won't harm the environment when breaking down.

We also ran into another issue, which is that in order to bond the carbon block powder together, manufacturers use non-biodegradable polyethylene. We managed to get the highest quality of any non-biodegradable plastic - inert, and non-toxic. See below why you can still dispose of your refills with organic waste.

Organic waste disposal

TAPP 2 refill cartridges are entirely made out of non-toxic materials which remain inert after decomposing. The cartridges contain a high percentage of biodegradable and compostable material and can be disposed of with organic waste. Please check with your local industrial composting plant. The device itself (without the refills) is made out of highly recyclable ABS polymers.

Biodegradable content: 74%
Casing (42%) made of Natureworks PLA has passed ASTM D-6400 Standard Specification for Compostable Plastics
Coconut Shell (32%) breaks down into: CO2 and water

Other product: 26%
Silicon (6%) breaks down into: amorphous silica, carbon dioxide, and water
UHMW (20%) does not biodegrade, but is inert and stable and doesn’t accumulate in marine life

Smart water filter & App

Innozen electronics

We wanted our filter to have a positive impact on the environment, but also we wanted to make sure that users would be aware of their impact. So we made TAPP 2 smarter than any previous water filter. By using the integrated bluetooth button, customer can trigger a notification on their iOS or Android device. This notification immediately opens the app, letting them know the current filter status, when it needs to be replaced and provides stats on how many plastic bottles and CO2 have been avoided.

But we went even further. We added a map to the TAPP App including all the public water refill points in the world. With this you now know where to refill your bottle wherever you are!

Key insights from making TAPP2 smart water filter

Everyone with experience of hardware told us hardware is hard and there would be many issues along the way. There was. Just to mention a few of the challenges:

  • Timelines were constantly missed and we ran into Chinese New Year losing another 1-2 months
  • Communication was really difficult between our team in Europe and the team in China
  • There wasn't enough glu or the glu wasn't strong enough to hold the pressure
  • PLA materials broke under high pressure
  • Quality Assurance wasn't managed tightly enough which meant that over 10% of the delivered products broke when customers used them in the beginning
  • Materials and manufacturing partners were changed by our partner without informing us

Our review of Innozen Electronics?

Choosing a partner for production China is hard. Innozen Electronics was recommended to us by a trusted source. Unfortunately a combination of poor communication, cutting corners in terms of quality and insufficient quality controls on our side had serious repercussions on our businesses. During 2018-2019 we lost over $500,000 in sales, returns, recalls and repairs. All of this could have been avoided. Therefore we cannot recommend Innozen Electronics as a product design partner in China.

Since then we've changed our manufacturing partner and vastly improved product quality.


Despite all the challenges TAPP2 smart water filter has been a huge success and it's now the top selling faucet water filter in Spain and quickly growing in other countries. But we could have done much better if we had been able to avoid the quality issues. Poor quality has a big impact on customer reviews, recommendations and this drives sales. Now we've fixed the issues but if we had avoided them from the start our growth would have been much faster.

And now, what is next? What do you think TAPP 3, 4 or even 5 should focus on? Write to us at or reply in the comment section.

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