Aerogel-based mold for mems fabrication and formation thereof

A method of fabricating a microelectromechanical structure, the method comprising:

• providing a substrate having an aerogel-based layer over a portion of the substrate, wherein the aerogel-based layer comprises an aerogel that is at least about 90% gas by volume and having a thickness less than about 1 mm;
• writing a structural feature in the aerogel-based layer, the structural feature having a surface contour that is substantially the same as a surface contour of at least a part of a micro electromechanical feature;
• depositing a dense material layer over the aerogel-based layer to form at least part of the microelectromechanical feature, wherein a portion of the dense material layer is directly attached to another portion of the substrate;
• and
• removing the aerogel-based layer.

A microelectromechanical structure comprising

• a substrate;
• a removable aerogel-based layer over a portion of the substrate, the aerogel-based layer comprising an aerogel that is at least about 90% gas by volume, the aerogel-based layer having at least one structural feature with a surface contour that is substantially the same as a surface contour of at least part of a microelectromechanical feature;
• and
• at least one dense material layer over the surface contour of the at least one structural feature of the aerogel-based layer, wherein a portion of the dense material layer is directly attached to another portion of the substrate, the at least one dense material layer comprising at least part of the microelectromechanical feature.