Background

Building energy consumption accounts for roughly forty percent of the total energy produced in the United States, most of which is still being generated by burning fossil fuels [1]. The predicted increase of the world population [2] will also add greatly to the future global energy demands in the constructed environment. Within buildings roughly a third of the energy is being spent on heating and cooling the interior environment. Building skins and architectural envelopes have a significant impact on the thermal conditions. In particular active and reactive interventions such as kinetic façade systems have been known to assist mechanical Heating Cooling and Ventilation and Air-conditioning (HVAC) systems.

The project development initially started with an exploration of heat transfer through construction materials including conduction, convection and radiation. Conduction in exterior wall systems can be modified by adding air spaces. They are instrumental in reducing the thermal transfer through materials assemblies. Convection could be addressed by designing a dynamic layer that could influence wind turbulences on the outer surface of the system. Radiation could be addressed through the use of thermochromic pigments, which can regulate the amount of solar energy emitted or absorbed in different outdoor temperatures.

These initial explorations led to the design of the Soft Barrier, which is a distributed soft robotic wall system that strives to control heat transfer through exterior architectural envelopes, by using air for the actuation mechanism as well as a vital material component in the assembly.

A similar type of system has already been developed and patented by Robert Alderman[3], but only focused on the conductive and radiation properties of an “inflatable and deflateable" heat insulation system.” Our proposal goes further by introducing smart materials and microcontrollers. This allows the design of a truly active and reactive system. Smart materials (Addington, 2005) are distinguished by their ability to respond to different stimuli in their surroundings with a significant change of their properties. They are their own sensors, actuators and they do not depend on conventional energy sources such as electricity. They can operate on ambient energy fluctuations such as changing light conditions or temperature differentials. The use of microcontrollers and sensors is instrumental in the creation of an adaptable design. It takes input from the environmental conditions as well as the human users.