A New Method for Searching for Free Fractional Charge Particles in Bulk   Matter
  We present a new experimental method for searching for free fractional charge in bulk matter; this new method derives from the traditional Millikan liquid drop method, but allows the use of much larger drops, 20 to 100 mm in diameter, compared to the traditional method that uses drops less than 15 mm in diameter. These larger drops provide the substantial advantage that it is then much easier to consistently generate drops containing liquid suspensions of powdered meteorites and other special minerals. These materials are of great importance in bulk searches for fractional charge particles that may have been produced in the early universe. 
Dinesh Loomba, Valerie Halyo, Eric R. Lee, Irwin T. Lee, Peter C. Kim   and Martin L. Perl