
A team of researchers has developed a 3D printed “bioshade” that automatically reacts to the environment.
The researchers sought to develop an energy-efficient solution to building shading. Typically, shades are placed on the inside of windows, but this requires manual effort, leading to inconsistent results. It would be far better if the energy did not travel through windows to complicate indoor heating and cooling.
The researchers envisioned a building facade that could automatically react to environmental conditions and deploy shading when required.
They leverage a technique called “4D Printing”. This is essentially the same as 3D printing, except that the objects produced are able to change their shape after printing with appropriate stimulus. Usually, this is done by printing layers of materials that react differently to heat, electricity, or other external signals.
In this case, the researchers used layers of cellulose and polyketone material that were triggered by humidity and temperature, the two factors controlling the human weather experience.
They devised a self-shaping module that would morph into a shaded position when conditions required it, using Grasshopper to generate the CAD models.
A module was produced by using dual extrusion FFF 3D printers, with a FELIX TEC 4 for the cellulose portions, and a TAZ 6 for other polymer components. Each module took around 30 minutes to produce, and four devices made the required 424 modules in 17 days.
The modules could react within 30 minutes to environmental changes. All 424 modules were produced and installed on a “solar wall” located in Freiburg, Germany.
Deployed for over a year, the Solar Wall showed that the modules did indeed curl appropriately when conditions changed. They were found also to be quite durable, incurring repeated cycles daily.
This was quite an experiment and demonstrated the concept of passive climate control for buildings. According to the study, significant energy savings were obtained by increasing shading in summer and decreasing shading in winter.
Savings occurred not only due to reduced energy to change building temperatures but also because no monitoring or control systems were required for the Solar Wall: it operates automatically.
Because the researchers demonstrated that these modules could be produced at a low cost, it is entirely possible the concept could be adopted by the construction industry. We could see building facades covered in passive 4D printed shaders in the future.
Via Nature (Hat tip to Benjamin)