Directed Assembly of Microstructures Using Bubble Latches

We introduce a highly flexible method for the assembly of microscale components using laser-activated bubble latching. Arbitrary structures are created through combining directed fluidic assembly and surface tension-driven latching. The bubbles are generated through laser degradation of the SU-8 tile. This gives the user control over the time and location of latching, as opposed to predefined latching locations in other microscale assembly methods. Shear force experiments show that each bubble is able to support a tensile force of 0.33μN. By utilizing the compressibility of bubbles, assembled objects are switched between rigid and flexible states, facilitating motion through irregular channel geometries. Further, through the use of bubble hinging at component corners, reconfiguration is quickly and effectively achieved. This novel hybrid approach to the assembly of microscale components offers significant controllability to the user.Copyright © 2011 by ASME