Tag and seal employing a micromachine artifact
A tamper resistant seal including a population of particles embedded in an adhesive, the population including at least one micromachine artifact of a predetermined physical shape.
1. A tamper resistant seal, comprising:
an adhesive matrix;
a population of particles embedded in the adhesive matrix, wherein the population includes at least one particle that is a micromachine artifact formed by a microelectronic and microelectromechanical technique to have a predetermined physical shape;
a frame embedded in the adhesive matrix, the frame being of a contiguous material which forms a perimeter surrounding the population of particles
wherein the micromachine artifact comprises a material selected from a group consisting essentially of monocrystalline or polycrystalline semiconductor material; and
wherein the micromachine artifact comprises a plurality of repeating features having a critical dimension of less than 500 μm.
2. The tamper resistant seal of claim 1 , wherein the physical shape or physical location of the at least one micromachine artifact within the seal identifies the seal.
3. The tamper resistant seal of claim 1 , wherein the population of particles comprises at least three structurally distinct micromachine artifacts, each having a different predetermined shape, the combination of the at least three artifacts identifying the seal.
4. The tamper resistant seal of claim 1 , wherein an outer edge of the at least one micromachine artifact includes the plurality of repeating features, each repeating feature having a side with a critical dimension no greater than 500 μm.
5. The tamper resistant seal of claim 1 , wherein the predetermined physical shape is defined in a first and second dimension and the artifact has a predetermined physical thickness in a third dimension which is less than a longest length of the artifact in the first or second dimension.
6. The tamper resistant seal of claim 5 , wherein the predetermined shape comprises a polygon, at least one side having a dimension smaller than the longest length.
7. The tamper resistant seal of claim 1 , wherein the micromachine artifact comprises at least one length greater than a millimeter.
8. The tamper resistant seal of claim 1 , wherein the frame is monocrystalline and includes alignment marks integrally formed into the frame material.
9. The tamper resistant seal of claim 1 , wherein the adhesive comprises a UV-curable acrylic resin.
10. The tamper resistant seal of claim 1 , wherein the population of particles further comprise randomly distributed specularly reflective particles of a random shape.