Micro-electromechanical system (MEMS) interferometer for FT-MIR spectroscopy

1. A micro-electromechanical system (MEMS) interferometer, comprising:

a pair of movable mirrors that are positioned along perpendicular axes, wherein each of the pair of movable mirrors is coupled to a mechanism comprising:

an electrostatic actuator driving a displacement amplification mechanism, wherein the displacement amplification mechanism comprises:

a symmetric fulcrum coupled to a central actuator of the electrostatic actuator; and

three serpentine release flexures, wherein the serpentine release flexures amplify a displacement from a central actuator of the electrostatic actuator to increase a motion of the movable mirror; and

the displacement amplification mechanism driving each of the pair of the movable mirrors; and

a beam splitter positioned at an intersection of the perpendicular axes extending through each movable mirror and the beam splitter; and

a metasurface microbolometer placed in line with the beam splitter to measure an intensity of a recombined beam from the pair of movable mirrors.

2. The MEMS interferometer of claim 1 , comprising a single chip.

3. The MEMS interferometer of claim 2 , wherein the single chip is 12 mm×12 mm.

4. The MEMS interferometer of claim 1 , wherein the electrostatic actuator comprises:

a central actuator attached to a movable comb, wherein the movable comb comprise grounded tines;

a positive comb comprising positive tines, wherein the positive tines are interspersed with the grounded tines on a first side of the movable comb;

a negative comb comprising negative tines, wherein the negative tines are interspersed with the grounded tines on a second side of the movable comb;

a sway stabilizer attached to the central actuator at one end; and

a coupling from the central actuator to the displacement amplification mechanism at an opposite end from the sway stabilizer.

5. The MEMS interferometer of claim 1 , wherein the displacement amplification mechanism increases a motion of the movable mirror by a factor of eight over the motion of the central actuator.

6. The MEMS interferometer of claim 1 , wherein the metasurface microbolometer comprises:

a metasurface tuned to absorb a radiation in a range of frequencies in the mid infrared;

a dielectric substrate disposed in contact with the metasuface;

a thermometric layer in contact with the dielectric substrate, wherein the dielectric substrate separates the metasurface from the thermoelectric layer, and wherein the thermometric layer changes in resistivity with temperature changes; and

a readout integrated circuit to measure a response from the thermometric layer comprising a voltage drop across the contacts of the bridge with a constant bias current.

7. The MEMS interferometer of claim 6 , wherein the metasurface is an electrically conductive geometric pattern based on a geometrical inversion of the rhodonea conformal mapping contours.

8. The MEMS interferometer of claim 6 , wherein the metasurface comprises gold.

9. The MEMS interferometer of claim 6 , wherein the metasurface absorbs radiation through surface plasmon resonances.

10. The MEMS interferometer of claim 6 , wherein the metasurface is 120 nm in thickness.

11. The MEMS interferometer of claim 6 , wherein the metasurface is less than 30 nm in thickness.

12. The MEMS interferometer of claim 6 , wherein the metasurface has a diameter of 150 μm.

13. The MEMS interferometer of claim 6 , wherein the metasurface has a 35% fill factor.

14. The MEMS interferometer of claim 6 , wherein the metasurface has a detectivity (D*) of 1×10 10 cm*sqrt(Hz)/W at 333 K at a bias current of 75 μA.

15. The MEMS interferometer of claim 6 , wherein the metasurface has a noise equivalent difference temperature (NEDT) of 1 mK at a bias current of 75 μA.

16. The MEMS interferometer of claim 6 , wherein the thermometric layer comprises undoped vanadium oxide (VO 2 ).

17. The MEMS interferometer of claim 6 , wherein the thermometric layer is 500 nm in thickness.

18. The MEMS interferometer of claim 6 , wherein the thermometric layer is less than 40 nm in thickness.

19. The MEMS interferometer of claim 6 , wherein the dielectric substrate comprises silicon nitride (Si 3 N 4 ).

20. The MEMS interferometer of claim 6 , wherein the dielectric substrate is about nm in thickness.

21. The MEMS interferometer of claim 6 , wherein the dielectric substrate is 100 nm in thickness.

22. The MEMS interferometer of claim 6 , wherein the dielectric substrate is separated from the readout integrated circuit by an airgap.

23. The MEMS interferometer of claim 1 , wherein the metasurface microbolometer has a broadband absorption of more than 90% in a wavenumber range of 1500 to 600 cm −1 .

24. The MEMS interferometer of claim 1 , wherein the metasurface microbolometer has an absorption bandwidth of 156% of full width half maximum (FWHM) centered on a wavenumber of 1070 cm −1 .