Major Areas of Opportunity - Implications of Emerging Micro-and Nanotechnologies - page 100

FIGURE 3-15 Silicon turbine from the micromachined gas turbine engine. SOURCE:
Epstein, A.H., S.D. Senturia, O. Al-Midani, G. Anathasuresh, A. Ayon, K. Breuer, K-S.
Chen, F.F. Ehrich, E. Esteve, L. Frechette, G. Gauba, R. Ghodssi, C. Groshenry, S.A.
Jacobson, J.L. Kerrebrock, J.H. Lang, C-C. Lin, A. London, J. Lopata, A. Mehra, J.O.
Mur Miranda, S. Nagle, D.J. Orr, E. Piekos, M.A. Schmidt, G. Shirley, S.M. Spearing,
C.S. Tan, Y-S. Tzeng, and I.A. Waitz. 1997. Micro-heat engines, gas turbines, and rocket
engines—The MIT microengine project, AIAA Paper 1997-1773. Reston, Va.: American
Institute of Aeronautics and Astronautics.
and a total mass of 57 grams, and it transmits live color images to a ground-based
operator. An order-of-magnitude increase in cruising time is required, indicating
the need for micro-combustion engines or generators. A single 100-millinewton
thrust engine is sufficient to power a 50-gram gross takeoff weight vehicle (about
6-inch characteristic length) with a 50-kilometer range at 60 knots flight speed.
More advanced MAVs could use five to ten engines to generate vertical lift
directly, thus enabling both 60-knot standard flight using efficient wing-gener-
ated lift plus hovering and low-speed capability for maneuvering within build-
ings and caves. Insect-sized flyers, an order of magnitude or more smaller than
the MAVs currently under development may be feasible within the next two
decades.
Batch-fabricated micro-turbine engines can be used on larger vehicles as
well since multiple engines can be used as vehicle size increases. Several thou-