Design Rules for Micro Fallingwater

For our microscopic model of Frank Lloyd Wright's masterpiece we used a fabrication technology that allows us to create tiny structures on a silicon wafer. This so-called SCREAM process (for Single Crystal Reactive Etching and Metallization) has permitted researchers to build a wide variety of sensors and actuators integrated on a chip, from accelerometers to micro motion arrays, from micro snap fasteners to fully integrated scanning tunneling microscopes.

MEMS (Micro Electro Mechanical Systems) technology opens up tremendous possibilities for small, complex systems that combine electronic and mechanical components. However, the fabrication process does not allow arbitrary shapes. There are significant constraints on the designs permissible by the SCREAM process, summarized in the following design rules:

Three Layers is the maximum any structure can have, and each layer is between 5 and 10 micrometer high.
Top Layer: Its ground-plan is any two-dimensional shape, with preference to rectangular polygons. This layer will be an extruded body of 5 to 10 micrometer height.
Middle Layer: Permitted is any shape that has the Top Layer as a subset, so that the ground-plan of the Top Layer is fully included in the ground-plan of the Middle Layer.
Bottom Layer: This layer is given by the Middle Layer shrunk by about 1 micrometer. This means that any structure in the Middle Layer that is less than 2 micrometer wide will be a free, released beam or cantilever.
There are also rules for electrical connections that we do not need to worry about (unless we decide to install LEDs in the building).

More about Building Micro Fallingwater

Back to the Invisible Cantilever.