{"id":1997,"date":"2010-07-14T10:21:32","date_gmt":"2010-07-14T14:21:32","guid":{"rendered":"https:\/\/wpmu2.mit.local\/?p=1997"},"modified":"2010-07-14T10:21:32","modified_gmt":"2010-07-14T14:21:32","slug":"mems-pressure-sensor-arrays-for-passive-underwater-navigation","status":"publish","type":"post","link":"https:\/\/wpmu2.mit.local\/mems-pressure-sensor-arrays-for-passive-underwater-navigation\/","title":{"rendered":"MEMS Pressure-sensor Arrays for Passive Underwater Navigation"},"content":{"rendered":"
\"Figure<\/a>

Figure 1: Pressure-sensor array applications.<\/p><\/div>\n

A novel sensing technology for unmanned undersea vehicles (UUVs) is under development. The project is inspired by the lateral line sensory organ in fish, which enables some species to form three-dimensional maps of their surroundings [1<\/a>]<\/sup> [2<\/a>]<\/sup>. The canal subsystem of the organ can be described as an array of pressure-sensors [3<\/a>]<\/sup>. Interpreting the spatial pressure gradients allows fish to perform a variety of actions, from tracking prey [4<\/a>]<\/sup> to recognizing nearby objects [2<\/a>]<\/sup>.\u00a0 It also aids schooling [5<\/a>]<\/sup>. Similarly, by measuring pressure variations on a vehicle surface, an engineered dense pressure-sensor array allows the identification and location of obstacles for navigation (Figure 1). We are demonstrating proof-of-concept by fabricating such MEMS pressure sensors by using KOH etching techniques on SOI wafers to construct strain-gauge diaphragms.<\/p>\n

\"Figure<\/a>

Figure 2: Diagram of pressure-sensor array with basic structure depicted.<\/p><\/div>\n

The system consists of arrays of hundreds of pressure-sensors spaced about 2 mm apart on etched silicon and Pyrex wafers. The sensors are arranged over a surface in various configurations (Figure 2). The target pressure resolution for a sensor is 1 Pa, which corresponds to the noiseless disturbance created by the presence of a 0.1-m radius cylinder in a flow of 0.5 m\/s at a distance of 1.5 m. A key feature of a sensor is the flexible diaphragm, which is a thin (20-\u03bcm) layer of silicon attached at the edges to a silicon cavity. The strain on the diaphragm due to pressure differences across the diaphragm is measured. At this stage, the individual MEMS pressure sensors are being constructed and tested.<\/p>\n

In parallel to the construction of a sensor array, techniques are being developed to interpret the signals from a dense pressure array by detecting and characterizing wake structures such as vortices and building a library of pressure distributions corresponding to basic flow obstructions.\u00a0 In order to develop these algorithms, experiments are being performed on coarse arrays of commercial pressure-sensors.<\/p>\n

\r\nReferences
  1. J.C. Montgomery, S. Coombs, and C.F. Baker, \u201cThe mechanosensory lateral line system of the hypogean form of Astyanax fasciatus<\/em>,\u201d Environmental Biology of Fishes<\/em>, vol. 62, pp. 87-96, 2001. [↩<\/a>]<\/li>
  2. C. von Campenhausen, I. Riess, and R. Weissert, \u201cDetection of stationary objects by the blind cave fish Anoptichthys jordani <\/em>(Characidae),\u201d Journal of Computational Physiology A<\/em>, vol. 143, pp. 369-374, 1981. [↩<\/a>] [↩<\/a>]<\/li>
  3. S. Coombs, \u201cSmart skins: Information processing by lateral line flow sensors,\u201d Autonomous Robots<\/em>, vol. 11, pp. 255-261, 2001. [↩<\/a>]<\/li>
  4. [4] K. Pohlmann, J. Atema, and T. Breithaupt, \u201cThe importance of the lateral line in nocturnal predation of piscivorous catfish,\u201d Journal of Experimental Biology<\/em>, vol. 207, pp. 2971-2978, 2004. [↩<\/a>]<\/li>
  5. T.J. Pitcher, B.L. Partridge, and C. S. Wardle, \u201cA blind fish can school,\u201d Science<\/em>, vol. 194, pp. 963-965, 1976. [↩<\/a>]<\/li><\/ol><\/div>","protected":false},"excerpt":{"rendered":"

    A novel sensing technology for unmanned undersea vehicles (UUVs) is under development. The project is inspired by the lateral line…<\/p>\n<\/div>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[29],"tags":[56,4215],"_links":{"self":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/1997"}],"collection":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/comments?post=1997"}],"version-history":[{"count":2,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/1997\/revisions"}],"predecessor-version":[{"id":2001,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/1997\/revisions\/2001"}],"wp:attachment":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/media?parent=1997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/categories?post=1997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/tags?post=1997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}