Improving yield, accuracy and complexity in surface tension self-assembled MOEMS

Surface tension-powered self-assembly of microstructures - The state-of-the-art

“…Angular errors as low as a few minutes of arc (similar to the estimate in Section V-B) have been obtained for 45 and 90 rotated structures using this process, when combined with the limiters shown in Fig. 10(d) and (f) [103]. There are three reasons for this high precision.…”

“…As a result, they are mainly due to bending, and close agreement may be reached with the prediction of simple structural models, which take this into account [103]. Minimizing deformation is important for applications such as MOEMS.…”

“…Fig. 7(a) shows a process developed at Imperial College, based on mechanical parts formed in BSOI (with a 5 m thick bonded layer patterned by DRIE), with photoresist as the meltable material [102], [103]. This process has been used to assemble parts with spans of up to 1 mm, using very compact driver pads (with lengths of 250 m, widths m and heights m).…”

“…Assembly is sequential, because the central part must rotate further than the others. However, the timings are not crucial; the stop must simply be formed before the central part reaches it [103]. …”

Beyond molecules: Self-assembly of mesoscopic and macroscopic components

“…This technique uses conventional lithographic technology to make planar precursors to the 3D microstructures. These structures then fold spontaneously into 3D shapes via capillary forces (69,70) or electrical activation of conjugated polymers (71). The processes used in this type of fabrication involve multiple steps of fabrication, however, and the folding processes are early in their development.…”