A microelectromechanical systems die including a thermally conductive substrate including an outer surface, a plurality of low mass sensing structures disposed within the thermally conductive substrate to form a plurality of inter-structure spaces therebetween, each of the plurality of low mass sensing structures include a sensing structure proximal top surface, a sensing structure distal top surface, and a sensing structure width dimension.

A document and an Anti-counterfeiting method for use in such documents are described. Said document and Anti-counterfeiting method include introducing a plurality of raised nanoscopic to microscopic structures, here referred to as reconfigurable structures, formed over a polymer substrate to induce optical changes, such as structural color and/or optical fuzziness. Dynamic changes using liquids provide the anti-counterfeiting measures.

A method of fabricating a micro-electrical-mechanical system (MEMS) transducer comprises the steps of forming a membrane on a substrate, and forming a back-volume in the substrate. The step of forming a back-volume in the substrate comprises the steps of forming a first back-volume portion and a second back-volume portion, the first back-volume portion being separated from the second back-volume portion by a step in a sidewall of the back-volume. The cross-sectional area of the second back-volume portion can be made greater than the cross-sectional area of the membrane, thereby enabling the back-volume to be increased without being constrained by the cross-sectional area of the membrane. The back-volume may comprise a third back-volume portion. The third back-volume portion enables the effective diameter of the membrane to be formed more accurately.

A method of fabricating a micro-electrical-mechanical system (MEMS) transducer comprises the steps of forming a membrane on a substrate, and forming a back-volume in the substrate. The step of forming a back-volume in the substrate comprises the steps of forming a first back-volume portion and a second back-volume portion, the first back-volume portion being separated from the second back-volume portion by a step in a sidewall of the back-volume. The cross-sectional area of the second back-volume portion can be made greater than the cross-sectional area of the membrane, thereby enabling the back-volume to be increased without being constrained by the cross-sectional area of the membrane. The back-volume may comprise a third back-volume portion. The third back-volume portion enables the effective diameter of the membrane to be formed more accurately.

A microelectromechanical systems die including a thermally conductive substrate including an outer surface, a plurality of low mass sensing structures disposed within the thermally conductive substrate to form a plurality of inter-structure spaces therebetween, each of the plurality of low mass sensing structures include a sensing structure proximal top surface, a sensing structure distal top surface, and a sensing structure width dimension.

A MEMS device including a first proof mass, a first magnetized magnetic material disposed partially on a surface of the first proof mass, a first spring anchored to a substrate to support the first proof mass, and a first sensing element coupled to the first proof mass and operable to sense the motion of the first proof mass caused by an ambient acceleration. The MEMS device further includes a second sensing element coupled to the first proof mass and operable to sense the motion of the first proof mass caused by an ambient magnetic field.