noun, Biology. 1. an orientation of an organism to an external stimulus, as light, especially by growth rather than by movement. Origin of tropism. 1895-1900. First recorded in 1895-1900; independent use of -tropism. Related forms. tropismatic.
Friction on as-grown graphene (Fig. 1c) is ultra-low and rather uniform with its magnitude close to the previous reports4. In contrast, friction on graphene after ï¬uorination becomes
The present invention is a thermally expandable composition for use in actuators comprising about 10-50 weight percent graphite particles dispersed in a wax or polymer. The composition has a thermal conductivity of at least 0.2 watts/(meterÂ°C) at ambient temperatures. Ambient temperatures refer to temperatures in the range 22-28Â°C.