MEMS/NEMS TECHNOLOGY APPLIED TO IN-SITU PLANETARY EXPLORATION

Micro/Nano Electro Mechanical Systems (MEMS/NEMS) technology is being applied at JPL to develop novel devices and instruments for In-Situ Planetary Exploration. Examples of these applications are described below.

Electron-beam excited x-ray fluorescence of materials is enabled in air, in the Atmospheric Electron X-ray Spectrometer (AEXS), by means of a micro-fabricated, electron-transmissive membrane. The 200-nm-thick membrane is capable of withstanding a differential pressure of one atmosphere and isolates the vacuum of the electron source from the atmospheric pressure ambient. We have demonstrated proof-of-principle for the AEXS instrument concept and are working towards building a portable instrument prototype.

The Force Detected Nuclear Magnetic Resonance Spectrometer (FDNMRS) is a novel, microfabricated device capable of detecting and distinguishing the presence of water and other organic compounds in physisorbed or chemisorbed states. The ultimate device is only 2 mm in diameter is and capable of characterizing 60-micron-sized particles. Proof-of-principle for the spectrometer was demonstrated using a mostly conventionally-machined spectrometer that was 25 times the size of the ultimate device. The proton NMR peak from a water droplet was successfully detected as were J-coupling splittings in an organic molecule using spin-echo techniques. Work is progressing on the realization of the MEMS-scale device.

A high aspect ratio lithography technique know by its acronym LIGA is being used to fabricate a micro-quadrupole filter for mass spectrometer applications. The process involves the electroplating of nickel within a "mold" created from a thick-film (2-3 mm thick) Poly Methyl MethAcrylate (PMMA) film.

Finally, an electron beam lithography fabricated NEMS device is being developed for "Single Molecule Detection". The so-called Force Detected Optical Spectrometer (FDOS) works on the principle of dipole-dipole interactions causing a nanomechanical resonator to vibrate at frequencies of approx. 500 MHz. This work is very preliminary and the principle of the device and some initial results will be described.