Self-assembly of gears at a fluid/air interface

Journal of the American Chemical Society

Volumn 125, Issue 26, 2003, Pages 7948-7958

  Ng, Jessamine M K ^a   Fuerstman, Michael J ^a   Grzybowski, Bartosz A ^a   Stone, Howard A ^a   Whitesides, George M ^a  

^a HARVARD UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CAPILLARITY; HYDRODYNAMICS; LITHOGRAPHY; SELF ASSEMBLY; TORQUE;

HYDRODYNAMIC SHEAR;

GEARS;

DIMETICONE;

AIR; ARTICLE; CHEMICAL COMPOSITION; DEVICE; DYNAMICS; ENERGY; FORCE; HYDRODYNAMICS; LIQUID; MAGNETISM; MECHANICS; MOLECULAR INTERACTION; MOTION; SHEAR STRESS; SYNTHESIS; SYSTEM ANALYSIS; TORQUE;

EID: 0038202150     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja0347235     Document Type: Article

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34. A pinion is defined as a small gear that engages a larger gear. In this text, gears can be engaged either by physical contact (mechanical) or by mediation through a fluid (hydrodynamic or capillary).
35. In this text, we present magnetic pinions having the shape of either a ring (e.g., Figures 3, 4, 6, and 9) or a disk (e.g., Figures 7 and 8). There is no functional difference between these two types of pinions, as both of these pinions rotate at the same angular velocity as the rotating bar magnet.
36. The dependence of the operation of these gears on capillary forces is discussed in the section "Pitch: Toothed Gears".
37. In this text, we present magnetic pinions that drive diamagnetic rings by hydrodynamic shear that have either physical teeth (e.g., Figures 6 and 9) or no physical teeth (e.g., Figures 7 and 8). There is no difference between the effects of these pinions, since both types of pinions rotate at the same angular velocity as the rotating bar magnet, and both drive the diamagnetic rings by hydrodynamic shear (thus they do not require physical contact with the rings to operate).
38. Please see section "Derivation of Eq 1".
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48. This motion is the same as that produced by the driving gear in Figure 4A, i.e., when a magnetic pinion drives a ring gear by hydrodynamic shear.
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53. Pictures of mechanical gears were adapted from the following sources: http://www.seisa.co.jp/english/e_uchihaguruma.htm, http://www.mit.edu/afs/athena/course/2/2.972/www/reports/torque_converter/ torque_converter.htm, and http://www.howstuffworks.com/gear2.htm.