Meso/micro scale combustion systems are being developed mainly for miniaturized propulsion systems and unmanned vehicles' on-board power systems. Micro gas turbines, for power supply in remote applications, is another important utilization for meso-micro scale combustion systems.

The advantage of micro combustion systems is their high energy density compared to batteries, hence making them a possible alternative for portable devices as well as small unmanned vehicles, as Khalid said.

You will find here a good article about micro combustion research and development, with possible applicaitons in the introduction:

http://engine.princeton.edu/Publications/Ju_2011_2.pdf

Some of the examples are

• Orbit change and attitude control of microspacecraft

• Precise positioning control of spacecraft constellations (formation flying) for

interferometry missions (gravity wave detection, planet searches around distant solarsystems), communications, and earth observations

• Small spacecraft propulsion for inspection and repair of large spacecraft

• Small spacecraft propulsion for decoys and active protection of large spacecraft

• Sample return missions from asteroids

• Insertion into final orbits when microspacecraft are launched as a secondary payload