Microscale three-dimensional electric devices and methods of making the same
Functionalized microscale 3 D devices and methods of making the same. The 3 D microdevice can be realized with the combination of top-down (lithographic) and bottom-up (origami-inspired self-assembly) processes. The origami-inspired self-assembly approach combined with a top-down process can realize 3 D microscale polyhedral structures with metal/semiconductor materials patterned on dielectric materials. In some embodiments, the functionalized 3 D microdevices include resonator-based passive sensors, i.e. split ring resonators (SRRs), on 3 D, transparent, free-standing, dielectric media (Al 2 O 3 ).
1. A method of making a functionalized 3D microdevice, the method comprising:
forming a 2D intermediate structure including a plurality of micropanels and hinges, wherein each micropanel includes:
a metal frame,
a window supported within the frame, the window formed of a dielectric material,
a microscale conductive pattern formed on the window;
wherein the micropanels are connected to one another and arranged in an array, and further wherein a respective one of the hinges extends between and interconnects immediately adjacent ones of the panels within the array; and
heating the 2D intermediate structure, wherein the step of heating includes each of the hinges self-folding to transition the 2D intermediate structure into a functionalized 3D microdevice.
2. The method of claim 1 , wherein the step of forming includes:
forming a sacrificial layer over a substrate;
depositing a first protection layer over the sacrificial layer; and
depositing a window material over the first protection layer so as to define the window of each of the panels.
3. The method of claim 2 , wherein the step of forming further includes:
removing the sacrificial layer to release the 2D intermediate structure from the substrate.
4. The method of claim 3 , wherein the sacrificial layer is poly(methyl methacrylate).
5. The method of claim 4 , wherein the step of removing the sacrificial layer includes dissolving the sacrificial layer in an organic solvent.
6. The method of claim 4 , wherein the step of depositing a first protection layer includes:
depositing a first sub-layer including chromium onto the sacrificial layer; and
depositing a second sub-layer including copper onto the first sub-layer.
7. The method of claim 2 , wherein the step of forming further includes:
depositing a second protection layer over the window material.
8. The method of claim 7 , wherein the step of forming further includes:
depositing a conductive pattern material over the first protection layer prior to the step of depositing the window material to define the microscale conductive pattern of each of the panels.
9. The method of claim 8 , wherein the step of forming further includes:
depositing a frame material over the second protection layer to define the frame of each of the panels.
10. The method of claim 9 , wherein the step of forming further includes:
depositing a hinge material over a portion of the frame material and a portion of the second protection layer to define the plurality of hinges.
11. The method of claim 10 , wherein the step of forming further includes:
removing the sacrificial layer to release the 2D intermediate structure from the substrate following the step of depositing the hinge material;
wherein the step of removing includes at least a portion of the first protection layer and an at least portion of the second protection layer remaining with the released 2D intermediate structure.
12. The method of claim 11 , wherein the step of forming further includes:
removing exposed portions of the first and second protection layers prior to the step of removing the sacrificial layer.
13. The method of claim 12 , further comprising:
removing exposed portions of the second protection layer following the step of heating the 2D intermediate structure.
14. The method of claim 1 , wherein the step of forming further includes:
forming a first joint structure at a free edge of a first panel of the plurality of panels; and
forming a second joint structure at a free edge of a second panel of the plurality of panel;
wherein the step of heating includes the first and second joint structures combining to form a completed joint with self-folding of the 2D intermediate structure.
15. The method of claim 1 , wherein the window of each of the panels is an aluminum oxide film.
16. The method of claim 1 , wherein the frame of each of the panels includes nickel, and further wherein each of the hinges includes solder.
17. The method of claim 1 , wherein the microscale conductive pattern of each of the panels is formed of a material selected from the group consisting of metal, metal alloy, insulator, and semiconductor material.
18. The method of claim 1 , wherein the microscale conductive pattern of at least one of the panels includes an array of split ring resonators.
19. The method of claim 18 , wherein the microscale conductive pattern of each of the panels is an array of split ring resonators.
20. The method of claim 1 , wherein the functionalized 3D microdevice has a polyhedral shape and defines an open interior volume.