Three-dimensional micro self-assembly using bridging flocculation

This paper describes three-dimensional (3D) self-assembling microstructures . Bridging flocculation of PAAM (polyacrylamide) is used as a bonding force . The microstructures are made of Si. An Al2O3 layer is deposited on a part of the surfaces for connection. By controlling the pH of the system, the b onding force acts only between the surfaces of Si and Al3O3. Therefore, the convex area can be connected to the concave one when they collide. These s tructures are fabricated mainly by oxidation and KOH anisotropic etching. W e also demonstrate that the behavior of the self-assembling system can be d escribed by chemical formulae and analyzed by rate equations. (C) 2000 Else vier Science S.A. All rights reserved.