Living Tiles

1. Mutual interest and research area crossing

We started the ideation process trying to identify an area of intervention and an approach that we thought we had in common. To do so we took into account our interests in terms of design and then crossed them to see exactly what were the ones that were interesting and meaningful to the both of us.

We ended up choosing this 5 topics/areas of interests:

1- New sustainable materials (bio/recycled exc.)

2- Inspiration from nature(function, aesthetic)

3- Self sufficiency/ off grid living

4- Low, ancestral tech

5- Digital (bio)fabrication

Given those interests and areas of intervention, we started building from that, and decided that we really liked the combination between taking inspiration from ancient techniques to solve actual problems, and combining it with the potential of new technologies like digital fabrication. By using this approach, we wanted to solve a climate-related problem.

This thought process led to our research question that guided us through the whole process:

How can we take inspiration from ancient techniques to develop a solution incorporating new technologies to solve a climate-related problem in the city?

2. Purpose: What is the artifact supposed to do? Not do?

Context: Climate change in Barcelona

In recent years, Barcelona and Catalonia have experienced increasingly extreme climate events, marked by both intense rainfall episodes and prolonged heat waves. In Barcelona metropolitan area, most of the surface is sealed by asphalt, concrete, or paving, preventing natural water infiltration into the soil, and contributing to flooding events.

At the same time, longer and more frequent heat waves amplify the urban heat island effect, as impermeable, dark surfaces absorb and retain heat, increasing thermal stress and health risks for vulnerable populations. These conditions expose a critical failure of urban design: the systematic disconnection between the city and the soil beneath it.

Purpose :

LivingTiles proposes an alliance with soil as a living climate infrastructure. Instead of treating the ground as a passive, inert surface, we want to reactivate the soil’s natural capacity to regulate climate, by absorbing water, storing moisture, and cooling the environment through evapotranspiration.

The proposal consists of responsive, permeable tiles that enhance the soil’s ability to infiltrate rainwater (flood mitigation) and evapotranspirate moisture (urban cooling), reducing surface runoff and lowering ambient temperatures. Made from upcycled waste materials, concrete and clay, our project reimagines the ground not as a barrier, but as an active agent in climate adaptation.

3. How do you fabricate? Key fabrication processes and steps

We aimed to integrate recipe for water infiltration & cooling effect.

Criteria for cooling:

• High albedo → reflect solar radiation
• Evaporative cooling → water battery in hydrogel
• Air chambers as a natural heat sink

Criteria for water infiltration:

• Porosity, space in between joints

3.1. Making Surface Tile

Mold

• Recipe: 300ml water, 120gr gelatine, 80ml glycerine
• Steps: Mix ingredients in a hot pot. Wait for it to cool a bit for 10-15 minutes before it solidifies. Add the mix into the negative (3D printed tile in box). Let it cool down and put it in the fridge to accelerate solidification.

Clay-based Tile

Recipe: White earthenware clay 500 g, crushed oyster shell (coarse, 1–3 mm) 75 g, fine sand 50 g, water 60ml, coarse sawdust 50g

Steps:

1- Break clay into small chunks (size of lentils)

2- Sprinkle half the oyster shell + sand

3- Crush + smear clay chunks

4- Add remaining dry materials

5- Crush again until evenly distributed

6- Mist water slowly only if needed

7- Press into mold or hand-compress

9- Dry very slowly

10- Cover loosely with plastic for 24h

11- Then uncover gradually over 2–3 days

Aereocrete Tile

Recipe: 1 part of cement, 2 part of a foamy mixture made of: 60 ml dishwasher soap, 15 grams of gum xantham, 1 lt of water, a splash of isopropyl alcohol

Steps:

1- Measure all the ingredients for the foamy mixture

2- Add a splash of isopropyl alcohol to the xantham gum and mix until absorbed

3- Add the soap and the water to the mixture

4- Mix with a big spoon until you obtain a homogeneous texture (around 5 minutes)

5- Let the foamy mixture rest for 10-15 minutes so that the gum can make its work of thickening.

6- Add the foamy mixture to the concrete, following the proportion of 1 part of concrete for 2 parts of foamy mixture

7- Stir the mixture with the help of a tool, better if electric powered ( we used a blender with a kitchen whisk attached). The longer you mix the more you will incorporate air and the more airy the structure of the aereocrete will be. Ideally when you see some bubbles on the surface of the material when stopping the mixing, the material is ready. We were satisfied with around 10 minutes of mixing.

8- Pour the mixture into the mold

9- Wait for the material to dry ( around 7 days)

10- Take off the artifact from the mold

3.2. Making Honeycomb Hydroceramic Layer

For this layer we created a honeycomb structure of clay with pockets where we placed hydrogel beads inside. The purpose of hydro-ceramic is to store water, allow reswelling after rain, and contribute to evaporative cooling

Clay matrix

We choose a honeycomb structure for clay matrix because it helps to generate humidity with geometry and we can use the clay pockets to protect the hydrogel beads

3D modeling: We designed the honeycomb pattern in Rhinoceros, starting from one line of structure and arraying it since it was modular. By doing so we obtained a honeycomb patterned structure of 160x160mm that is both structurally strong and suits the purpose of having empty chambers that would help transpiration, cooling of air and flowing of water.

Recipe of clay (water percentage)

Test #1: 15% clay in water, 500gr clay + 75ml

Test #2: 12% of clay in water, 500gr clay + 60ml water

Clay 3D Printing

Hardware parameters:

-Placed a 4mm nozzle.

-Air compressor pressure about 0.8 to 1.0 bars

Software parameters:

We used various softwares to be able to have the right communication with the hacked clay 3d printer to obtain what we wanted. In detail we had to use Grasshopper, Mamba and Repetier Host to be sure that the machine would do the right path while printing, without unnecessary and “dangerous” jumps between the parts.

Grasshopper / Mamba: Open Rhinoceros and then Grasshopper. Go to food4rhino.com/en/app/mamba?lang=es# and download “mamba example file 7.9.1”

Software steps:

1- Open the example file and import your geometry defining line, the printer will print following a curve path given by this curve that defines your geometry. For instance, given that we had a honeycomb pattern with a thickness of 4mm, we took the perimeter shape and offset it by 2 mm to have the center curve.

2- Select the curve in Rhino, and in the example file in the “machine configuration and automatic geometry location” panel, right click on the geometry button (orange), then select “set one geometry”.

3- In the following tab to the right, under “create base” select “false”(double click), set the nozzle diameter and slicing distance according to your needs, then click the button in the blue circle and wait a bit because it might take some time.

4- Finally, to the extreme right part of the file and in the yellow box you’ll find a gcode, right click on it and select “copy data only”.

5- Now open the program ”Repetier Host” and connect the printer with the “connect” tab on the top left.

6- On the right part of the screen open the “print preview” tab and select “edit gcode”.

7- Finally paste the gcode in the tab and send the print.

8- Repetier parameters for printing: feedrate: 296, flowrate: 69, Fan: 18, Bed temperature: 24

Physical steps

9- Mixed clay with water. We used old clay so we had to leave it resting for 1 hour so it would soften.

10- When the clay was soft enough, we mixed the clay with water evenly until reaching the right consistency for the mix to be easily extruded from the nozzle but at the same time not being too liquid. It was important to avoid any clumps in the mix.

11- We sucked clay filling by rotating the plastic container that attaches to the printer to avoid air pockets when 3D printing.

12- We plugged the plastic container with clay to the 3D printer

13- Linked the air compressor to the plastic container to push the material into the extruder

14- Opened the valves of the compressor to make air flow into the plastic chamber

15- Copied the G-code into Repetier.

16- Reviewed printing parameters and sent file

17- During the process of printing, we adjusted the air compressor when needed, the parameters went from 0.8 to 1.0 bars.

18- We printed each line of the honeycomb structure individually

Alginate-based hydrogel beads

We chose an alginate-based hydrogel because it absorbs water and acts as a water battery, and it is biodegradable. We adjusted the calcium concentration (usually of 2%) to keep the gel rechargeable, not brittle.

Recipe:

2% Alginate + 97% water

0.5% Calcium chloride in water = 5g per 1L water

Steps:

1- Dissolve sodium alginate in water; stir until fully hydrated (12 hours)
Prepare a shallow bath of calcium chloride solution.

2- Using a syringe or pipette, drop alginate solution drop by drop into the calcium bath.

3- Beads instantly gel; leave for 1–2 min, then rinse in water.

4- Let beads dry lightly if needed, or embed directly in clay pockets of matrix

4. System Diagram (diagram showing parts and relationships)

5. Challenges

The honeycomb structure consisted of 8 rows of geometry that we expected to be able to print together. However, we did not manage to do it due to a software problem. So we printed each one individually and placed them together manually. The printer was actually pretty slow and each block part took around 15 minutes. A future challenge would be to discover how to print it together or bind the structures together.

We changed the recipe of the Aereocrete and replaced the dishwasher soap with regular dish soap because we didn’t have it available, and this might have affected the final outcome of the mix.

The waiting time for the clay-based recipe and the aereocrete recipe was 5 to 7 days which in the framework of the exercise we did not account for. Currently we are waiting this time to test the material performance of the tiles in terms of water infiltration.

We tested just one recipe of hydrogel with alginate and placed it the clay pockets, the water evaporated but we haven't tested the water rechargeability of the hydrogel beads

6. References (links to papers, videos, resources and other projects)

Aereocrete

https://www.youtube.com/watch?v=z4_GxPHwqkA&t=322s

Mamba File

http://food4rhino.com/en/app/mamba?lang=es#

Clay 3D printing

https://github.com/fablabbcn/pasta-print-3d

https://www.youtube.com/watch?v=jNF1NYnVeio

https://www.hackster.io/group-2/form-follows-life-b5a7a0#toc-6--from-bitmap-to-contours-5

Passive Cooling Projects

https://www.dezeen.com/2025/06/24/3d-printed-partition-wall-brings-ancient-cooling-techniques/

https://ec.europa.eu/regional_policy/whats-new/newsroom/12-01-2026-spain-ceramic-paving-offers-a-new-approach-to-managing-urban-flood-risks_en

https://www.materialsource.co.uk/terracool-/

https://www.3dwasp.com/en/3d-printed-cooling-system-in-ceramic-terramound/

https://www.designboom.com/design/ant-studio-deki-cooling-installation-09-28-2017/

7. Future work - what would you do next with more time?

• Testing material performance, for example: test material strength with press, test material water absorption, infiltration and evapotranspiration.
• Testing new recipes for the tiles. We would like to test an extra typology of recipe which was more bio-based and more porous, but less structurally sound. It was made mainly of compost and biochar.
• Test other shapes of hydroceramic structure to confront heat resistance between them
• Develop and experiment new graphics for the top layer of the tile
• Embed sensors in tiles to collect relevant distributed data in events of flooding, heavy rain and urban heat waves.
• Apply the same core technique of passive cooling with hydroceramics to create other objects and installations for indoors or public space.
• Adjust/Tune the material performance objectives to create heat refuges or cooling habitats for nonhuman species