The continuous assembly and transfer of nanoelements

Patterned nanoelements on flexible polymeric substrates at micro/nano scale at high rate, low cost, and commercially viable route offer an opportunity for manufacturing devices with micro/nano scale features. These micro/nano scale now made with various nanoelement can enhance the device functionality in sensing and switching due to their improved conductivity and better mechanical properties.;In this research the fundamental understanding of high rate assembly and transfer of nanoelements has been developed. To achieve this objective, three sub topics were made. In the first step, the use of electrophoresis for the controlled assembly of CNT's on interdigitated templates has been shown. The time scale of assembly reported is shorter than the previously reported assembly time (60 seconds). The mass deposited was also predicted using the Hamaker's law. It is also shown that pre-patterned CNT's could be transferred from the rigid templates onto flexible polymeric substrates using a thermoforming process. The time scale of transfer is less than one minute (50 seconds) and was found to be dependent on polymer chemistry. It was found that CNT's preferentially transfer from Au electrode to non-polar polymeric substrates (polyurethane and polyethylene terephalathate glycol) in the thermoforming process.;In the second step, a novel process (Pulsed Electrophoresis) has been shown for the first time to assist the assembly of conducting polyaniline on gold nanowire interdigitated templates. This technique offers dynamic control over heat build-up, which has been a main drawback in the DC electrophoresis and AC dielectrophoresis as well as the main cause of nanowire template damage. The use of this technique allowed higher voltages to be applied, resulting in shorter assembly times (e.g., 17.4 seconds, assembly resolution of 100 nm). The pre-patterned templates with PANi deposition were subsequently used to transfer the nanoscale assembled PANi from the rigid templates to thermoplastic polyurethane using the thermoforming process.;In the third step, a novel integration of high rate pulsed electrophoretic assembly with thermally assisted transfer in a roll-to-roll process has been shown. This technique allowed the whole assembly and transfer process to take place in only 30 seconds. Further, a processing window is developed to control the percent area coverage of PANi with the aid of the belt speed. Also shown is the effect of different types of polymer on the quality of transfer, and it concluded that the transfer is affected by the polymer chemistry.