Abstract The Jet Propulsion Laboratory (JPL) routinely operates robotic spacecraftmillions of miles from the Earth. Current JPL missions include roving on Marsand observing the Sun, Earth, Saturn, comets and asteroids and deep space. Advances in high-fidelity modeling, simulation and visualization, high-precision sensors, instruments, harsh-environment electronics, autonomousoperations and on-board intelligence have enabled these challenging missions. Robotics capabilities developed at JPL have been applied to the MarsPathfinder, Mars Exploration Rover, Deep Space 1, EOS1 and other space missionsand used on many JPL research projects conducted for NASA, the US Department ofDefense and private industry. Although developed for space applications, thesetechnologies are also highly relevant to problems in terrestrial oil and gasexploration and production. Benefits from the deployment of these technologiesinclude greater precision, increased reliability, reduced uncertainty, increased productivity, reduced cost, and accelerated development schedules andtask completion times. In this paper, we provide a description of some of thesetechnologies and suggest how they might benefit the oil and gas industry Introduction JPL is a United States federally funded research and development center managedby the California Institute of Technology under a contract with NASA. Foundedmore than 50 years ago, JPL has been responsible for many pioneering spaceachievements including building and controlling Explorer 1 - the first USsatellite, the Ranger and Surveyor missions to land on the moon, Mariner 2 -the first spacecraft to Venus, the Viking missions to land on Mars, Voyager 1and 2 - the spacecraft that toured Jupiter, Saturn, Uranus and Neptune, theMars Pathfinder and Mars Exploration Rovers to drive on Mars and many others toobserve the planets, the sun, comets, and asteroids. In addition to itsplanetary exploration mission, JPL is actively involved in Earth science. Instruments and Earth-orbiting satellites developed at JPL study the geology, hydrology, ecology, oceanography, gravity and climate of the Earth. JPL alsoconducts missions focused beyond our solar system. Observations of deep spacehave yielded information about galaxy, star and planetary system formation, developed maps of our Milky Way galaxy and the universe, and found planets onother star systems. To enable these missions, JPL continues to developtechnologies in telecommunications, navigation, intelligent automation, imagingand image analyses, robotics, science instruments and micro- and nano-systems. In telecommunications, for example, JPL is able to collect data from theVoyager spacecraft beaming a 23 Watt signal from the edge of our solar systemmore than 14 billion kilometers away. There are a number of similarities between space applications and applicationsin the oil & gas industry (Oxnevad, 2010). In both cases, systems aredeployed at remote locations with limited access for intervention, maintenanceor repair. The operational environments are often hostile with harshtemperatures and pressures and corrosive materials. Reliability of systems isextremely important in space and in the oil and gas industry. Operations in therespective environments have high risk and the capabilities for replicatingenvironmental conditions for testing and failure mitigation are limited. Failures can be catastrophic and the cost, financially and in publicperception, can erode support for programs. Due to these similarities, there ismuch that the space and energy sectors can learn and benefit from eachother.

Miniature scroll pumps have been proposed as roughing pumps (low - vacuum pumps) for miniature scientific instruments (e.g., portable mass spectrometers and gas analyzers) that depend on vacuum. The larger scroll pumps used as roughing pumps in some older vacuum systems are fabricated by conventional machining. Typically, such an older scroll pump includes (1) an electric motor with an eccentric shaft to generate orbital motion of a scroll and (2) conventional bearings to restrict the orbital motion to a circle. The proposed miniature scroll pumps would differ from the prior, larger ones in both design and fabrication. A miniature scroll pump would include two scrolls: one mounted on a stationary baseplate and one on a flexure stage (see figure). An electromagnetic actuator in the form of two pairs of voice coils in a push-pull configuration would make the flexure stage move in the desired circular orbit. The capacitance between the scrolls would be monitored to provide position (gap) feedback to a control system that would adjust the drive signals applied to the voice coils to maintain the circular orbit as needed for precise sealing of the scrolls. To minimize power consumption and maximize precision of control, the flexure stage would be driven at the frequency of its mechanical resonance. The miniaturization of these pumps would entail both operational and manufacturing tolerances of <1 m. Such tight tolerances cannot be achieved easily by conventional machining of high-aspect-ratio structures like those of scroll-pump components. In addition, the vibrations of conventional motors and ball bearings exceed these tight tolerances by an order of magnitude. Therefore, the proposed pumps would be fabricated by the microfabrication method known by the German acronym LIGA ( lithographie, galvanoformung, abformung, which means lithography, electroforming, molding) because LIGA has been shown to be capable of providing the required tolerances at large aspect ratios.

Nano-engineered catalysts, and a method of fabricating them, have been developed in a continuing effort to improve the performances of direct methanol fuel cells as candidate power sources to supplant primary and secondary batteries in a variety of portable electronic products. In order to realize the potential for high energy densities (as much as 1.5 W h/g) of direct methanol fuel cells, it will be necessary to optimize the chemical compositions and geometric configurations of catalyst layers and electrode structures. High performance can be achieved when catalyst particles and electrode structures have the necessary small feature sizes (typically of the order of nanometers), large surface areas, optimal metal compositions, high porosity, and hydrophobicity. The present method involves electrodeposition of one or more catalytic metal(s) or a catalytic-metal/polytetrafluoroethylene nanocomposite on an alumina nanotemplate. The alumina nanotemplate is then dissolved, leaving the desired metal or metal/polytetrafluoroethylene-composite catalyst layer. Unlike some prior methods of making fine metal catalysts, this method does not involve processing at elevated temperature; all processing can be done at room temperature. In addition, this method involves fewer steps and is more amenable to scaling up for mass production. Alumina nanotemplates are porous alumina membranes that have been fabricated, variously, by anodizing either pure aluminum or aluminum that has been deposited on silicon by electronbeam evaporation. The diameters of the pores (7 to 300 nm), areal densities of pores (as much as 7 x 10(exp 10)sq cm), and lengths of pores (up to about 100 nm) can be tailored by selection of fabrication conditions. In a given case, the catalytic metal, catalytic metal alloy, or catalytic metal/ polytetrafluoroethylene composite is electrodeposited in the pores of the alumina nanotemplate. The dimensions of the pores, together with the electrodeposition conditions, determine the sizes and surface areas of the catalytic particles. Hence, the small features and large surface areas of the porosity translate to the desired small particle size and large surface area of the catalyst (see figure). When polytetrafluoroethylene is included, it is for the purpose of imparting hydrophobicity in order to prevent water from impeding the desired diffusion of gases through the catalyst layer. To incorporate polytetrafluoroethylene into a catalytic-metal/polytetrafluoroethylene nanocomposite, one suspends polytetrafluoroethylene nanoparticles in the electrodeposition solution. The polytetrafluoroethylene content can be varied to obtain the desired degree of hydrophobicity and permeability by gas.

A proposed method of design and fabrication of vacuum-packaged microelectromechanical systems (MEMS) and of individual microelectromechanical devices involves the use of multiple internal seal rings (MISRs) in conjunction with vias (through holes plated with metal for electrical contacts). The proposed method is compatible with mass production in a wafer-level fabrication process, in which the dozens of MEMS or individual microelectromechanical devices on a typical wafer are simultaneously vacuum packaged by bonding a capping wafer before the devices are singulated (cut apart by use of a dicing saw). In addition to being compatible with mass production, the proposed method would eliminate the need for some complex and expensive production steps and would yield more reliable vacuum seals. Conventionally, each MEMS or individual microelectromechanical device is fabricated as one of many identical units on a device wafer. Vacuum packaging is accomplished by bonding the device wafer to a capping wafer with metal seal rings (one ring surrounding each unit) that have been formed on the capping wafer. The electrical leads of each unit are laid out on what would otherwise be a flat surface of the device wafer, against which the seal ring is to be pressed for sealing. The resulting pattern of metal lines and their insulating oxide coverings presents a very rough and uneven surface, upon which it is difficult to pattern the sealing metal. Consequently, the seal is prone to leakage unless additional costly and complex planarization steps are performed before patterning the seal ring and bonding the wafers.

A micromachining process for the fabrication of vibratory microgyroscopes from silicon wafers, and aspects of the microgyroscope design that are inextricably linked with the fabrication process, have been modified in an effort to increase production yields from perspectives of both quantity and quality. Prior to the modifications, the effective production yield of working microgyroscopes was limited to one or less per wafer. The modifications are part of a continuing effort to improve the design and increase production yields to more than 30 working microgyroscopes per wafer. A discussion of pertinent aspects of the unmodified design and the unmodified fabrication process is prerequisite to a meaningful description of the modifications. The design of the microgyroscope package was not conducive to high yield and rapid testing of many microgyroscopes. One of the major impediments to high yield and testing was found to lie in vibration- isolation beams around the four edges of each microgyroscope, which beams were found to be unnecessary for achieving high resonance quality factors (Q values) characterizing the vibrations of petallike cantilevers. The fabrication process included an 8- m-deep plasma etch. The purpose of the etch was to create 8- m vertical gaps, below which were to be placed large gold evaporated electrodes and sensing pads to drive and sense resonant vibrations of the The process also included a step in which bridges between dies were cut to separate the dies. The etched areas must be kept clean and smooth (free of debris and spikes), because any object close to 8 m high in those areas would stop the vibrations. However, it was found that after the etch, there remained some spikes with heights that were, variously, almost as high or as high as the etch depth. It also was found that the cutting of bridges created silicon debris, some of which lodged in the 8- m gaps and some of which landed on top of the petals. The masses added to the petals by the debris altered resonance frequencies and/or Q values to unacceptable degrees. Hence, the spikes and the debris have been conjectured to cause most of the observed malfunctions of newly fabricated microgyroscopes. Another pertinent aspect of the unmodified design and process was the fabrication of electrodes and the 8- m capacitance gap on a 500- m-thick wafer, and the fabrication of a 3-mm-thick baseplate from another wafer. It was necessary to bond these wafers to each other in an assembly step that was later found to be superfluous in that it could be eliminated by a suitable modification of the design.

The development of MEMS generators using the Brayton cycle is attractive because of the cycle’s inherently high power to mass ratio. However, the introduction of such systems has been limited by manufacturing difficulties, as well as fundamental efficiency problems introduced by the MEMS size scales. In typical gas turbine based generators, high efficiencies are achieved through high Reynolds number operation, as well as by having tangential tip speeds close to sonic. In micro-devices these constraints become problematic. At standard atmospheric operating conditions and when the diameters of the compressors and turbines are from the order of several millimeters (micro-scale generators) to one or two centimeters (mesoscale generators), the Reynolds number is significantly decreased and the necessary rotational speeds can approach several millions of revolutions per minute (RPM). Fortunately, the efficiency problems associated with very small sizes can be ameliorated by adopting a closed, externally fired cycle operating with a heavy working gas at elevated pressures. Calculations show that by using xenon at an ambient pressure of 5 to 10 atm, and by adopting a meso-scale system, the operating RPM can be reduced to a few hundreds of thousand. Also, the Reynolds number will be increased by a factor of 10 to 20 over that of an equivalent system running on ambient air, thereby maintaining relatively high thermodynamic efficiencies. Another limitation of MEMS-scale rotating machinery is the difficulty in machining three-dimensional, aerodynamically efficient components. To address this issue a reasonably convenient technique for either reproducing or producing aerodynamically efficient, three-dimensional components has been developed for parts down to somewhat less than 1 cm characteristic size. The technique has been used to manufacture a 2.2 cm diameter centrifugal compressor. An initial experimental study of the compressor has been completed in xenon over a limited range of pressures. The experimental results come from a new small-scale test facility, in which compressors and turbines can operate separately to obtain detailed thermodynamic performance data at below atmospheric pressures up to 10 atmospheres. The precision and repeatability of the manufacturing process are of interest, as well as the feasibility of operating the compressor and the turbine at the high thermal efficiencies required of a useful, autonomous power generator. The externally fired cycle makes extensive use of counter-flow heat exchange for exhaust gas recuperation and combustion heating of the working gas. Estimates based on results reported in the paper, indicate useful power outputs of close to 2.8 kW and an overall system efficiency of around 0.3, for a system employing a 2.0 cm diameter compressor at an ambient pressure of 5 atm in xenon. As with any small thermally driven system, thermal management is a major issue and is discussed in the paper.

A process for transferring an entire wafer-level micromachined silicon structure for mating with and bonding to another such structure has been devised. This process is intended especially for use in wafer-level integration of microelectromechanical systems (MEMS) that have been fabricated on dissimilar substrates. Unlike in some older membrane-transfer processes, there is no use of wax or epoxy during transfer. In this process, the substrate of a wafer-level structure to be transferred serves as a carrier, and is etched away once the transfer has been completed. Another important feature of this process is that two electrodes constitutes an electrostatic actuator array. An SOI wafer and a silicon wafer (see Figure 1) are used as the carrier and electrode wafers, respectively. After oxidation, both wafers are patterned and etched to define a corrugation profile and electrode array, respectively. The polysilicon layer is deposited on the SOI wafer. The carrier wafer is bonded to the electrode wafer by using evaporated indium bumps. The piston pressure of 4 kPa is applied at 156 C in a vacuum chamber to provide hermetic sealing. The substrate of the SOI wafer is etched in a 25 weight percent TMAH bath at 80 C. The exposed buried oxide is then removed by using 49 percent HF droplets after an oxygen plasma ashing. The SOI top silicon layer is etched away by using an SF6 plasma to define the corrugation profile, followed by the HF droplet etching of the remaining oxide. The SF6 plasma with a shadow mask selectively etches the polysilicon membrane, if the transferred membrane structure needs to be patterned. Electrostatic actuators with various electrode gaps have been fabricated by this transfer technique. The gap between the transferred membrane and electrode substrate is very uniform ( 0.1 m across a wafer diameter of 100 mm, provided by optimizing the bonding control). Figure 2 depicts the finished product.

This paper describes a new fabrication technique developed for the construction of large area mirror membranes via the transfer of wafer-scale continuous membranes from one substrate to another. Using this technique, wafer-scale silicon mirror membranes have been successfully transferred without the use of sacrificial layers such as adhesives or polymers. This transfer technique has also been applied to the fabrication and transfer of 1 mum thick corrugated membrane actuators. These membrane actuators consist of several concentric-ring-type corrugations constructed within a polysilicon membrane. A typical polysilicon actuator membrane with an electrode gap of 1.5 mum, fabricated using the wafer-scale transfer technique, shows a vertical deflection of 0.4 mum at 55 V. The mirror membranes are constructed from single-crystal silicon, 10 cm in diameter, and have been successfully transferred in their entirety. Using a white-light interferometer, the measured average peak-to-valley surface figure error for the transferred single-crystal silicon mirror membranes is approximately 9 nm as measured over a 1 mm(2) membrane area. The wafer-scale membrane transfer technique demonstrated in this paper has the following benefits over previously reported transfer techniques: 1) No postassembly release process to remove sacrificial polymers is required. 2) The bonded interface is completely isolated from any acid, etchant, or solvent during the transfer process, ensuring a clean and uniform membrane surface. 3) Our technique is capable of transferring large, continuous membranes onto substrates.

This,paper reports on JPL's on-going research into MEMS gyroscopes. [1-4] This paper will describe the gyroscope's fabrication-methods, a new 8-electrode layout developed to improve performance and performance statistics of a batch of six gyroscopes (of the 8-electrode design) recently rate tested. Previously in our group, T. Tang and R. Gutierrez presented the results of their extensive use of ethylene diamine pyrocatechol (EDP) to deep-etch the inertial-sensitive resonators and post-supporting structures in a 4-electrode gyroscope design. Today, JPL is utilizing an in-house STS DRIE, replacing the old wet-etching steps. This has demonstrated superior precision in machining symmetry of the resonators, thus significantly reducing native rocking mode frequency-splits. A performance test of six gyros has shown an average, un-tuned, frequency split of 0.4% (11Hz split for rocking modes at 2.7KHz). The new JPL MEMS gyroscope has a unique 8-electrode layout, whose large electrodes can provide significant electrostatic softening of the resonator's springs. This allows matching of the Coriolis sensitive rocking modal frequencies to be improved from the native 0.4% to an average tuned frequency split of 0.02%. In separate tests, electrostatic tuning in the 8-electrode design has demonstrated the ability to match frequency-splits to within 10mHz, thus ensuring full degeneracy in even a very high Q device. In addition, a newly selected ceramic package-substrate has improved the device's dampening loses such that a mean Q of 28,000 was achieved in the six gyroscope tested. These Q's were measured via the ring-down time method. The improved fabrication development and other modifications described have led to the JPL's MEMS gyroscope achieving an average bias instability (Allan variance 1/f floor estimate) of 11degree/hr with best in the group being 2degree/hr. In an independent test, Honeywell Inc., reported one of our MEMS gyroscopes as achieving 1degree/hr bias instability flicker floor estimate measured at constant temperature.