The subject of healing and repair of damaged microelectrodes has become of particular interest as the use of integrated circuits, energy storage technologies, and sensors within modern devices has increased. As the dimensions of the electrodes shrink together with miniaturization of all the elements in modern electronic devices, there is a greater risk of mechanical-, thermal-, or chemical-induced fracture of the electrodes. In this research, a novel method of electrode healing using electrokinetically assembled carbon nanotube (CNT) bridges is presented. Utilizing the previously described step-wise CNT deposition process, conductive bridges were assembled across ever-larger electrode gaps, with the width of electrode gaps ranging from 20 microns to well over 170 microns. This work represents a significant milestone since the longest electrically conductive CNT bridge previously reported had a length of 75 microns. To secure the created conductive CNT bridges, they are fixed with a layer of electrodeposited polypyrrole (a conductive polymer). The resistance of the resulting CNT bridges, and its dependence on the size of the electrode gap, is evaluated and explained. Connecting electrodes via conductive CNT bridges can find many applications from nanoelectronics to neuroscience and tissue engineering.
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Dielectrophoresis-driven Assembly of Polymer Microbeads and Carbon Nanotubes Upon Fabricated Carbon Microelectrodes
Microparticulates placed in non-uniform electric field experience dielectrophoretic forces that can be utilized for the guided assembly of microparts. The presented study discusses two types of such guided micro-assemblies. We observe the self-assembly of carbon nanotubes (CNTs) into the conductive bridges between microelectrodes along the field lines. These conductive bridges are later fixed in place by the layer of electrodeposited conductive polymer Polypyrrole (PPy). Additionally, we report on using positive dielectrophoresis (pDEP) to attract polymer microbeads to the windows opened in the SU-8 photoresist on top of the microelectrodes. The electric field is getting shielded by the photoresist and thus the beads are attracted only to the bare electrodes opened in the photoresist via standard lithographic process. Presented techniques open new possibilities for the guided assembly of micro-components for sensors, actuators, microelectromechanical systems (MEMs), as well as for micro- and nano-electronic devices.
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- Award ID(s):
- 1661877
- NSF-PAR ID:
- 10110020
- Date Published:
- Journal Name:
- Proceedings of the World Congress of Micro- and NanoManufacturing
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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