Status : Verified
| Personal Name | Exconde, Mark Keanu James E. |
|---|---|
| Resource Title | Influence of Galvanic Reaction Parameters on Cu-Ag Core-Shell Nanowires for Piezoresistive Strain Sensing Applications |
| Date Issued | 19 July 2024 |
| Abstract | Copper (Cu) and silver (Ag) nanowires (NW) have been widely employed as conductive fillers in flexible electronic devices due to their high aspect ratios, leading to the formation of conductive networks in a polymeric substrate. However, Ag as a precious metal is expensive, while Cu oxidizes easily. Therefore, this study presents a solution-phase process for synthesizing Cu-Ag core-shell nanowires (CuAgNWs) via galvanic replacement. Increasing the reaction time, Cu:Ag molar ratio, and temperature resulted in thicker CuAgNWs with diameters up to 96 nm. This can be attributed to the enhanced Ag deposition on the {100} facets of the CuNWs, which correlates with the higher relative amounts of Ag determined by energy dispersive X-ray spectroscopy (EDS). Additionally, lower electrical resistance was attained by the CuAgNWs with thicker Ag shells. This is due to the improved oxidation stability of the NWs and the contribution of Ag in the overall conductivity of the CuAgNWs. X-ray diffraction (XRD) shows separate peaks due to Cu and Ag. Strong Cu peaks were observed, indicating excellent crystallinity. However, a flat and broad (200) Ag peak was identified from the XRD patterns of the CuAgNWs prepared at room temperature. Even at relatively high Ag concentration (up to 7.90 wt%), no other Ag peaks were present, possibly due to the thin Ag shell. This suggests the preferential deposition of Ag on the {100} facets of the CuNWs. The fabricated piezoresistive sensor made from CuAgNW film in a polydimethylsiloxane (PDMS) matrix exhibited a low sheet resistance of 13 Ω/sq due to the presence of numerous conductive networks. The sensor displayed high sensitivity (0.8439 kPa-1) and a linear response under compressive stresses up to 1.6 kPa. The sensor was employed in the detection of articular and muscular movements, showing stable electrical response under strained and unstrained states. |
| Degree Course | Master of Science in Materials Science and Engineering |
| Language | English |
| Keyword | Nanowires, Copper, Silver, Galvanic Reaction, Piezoresistive Device |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : F - Regular work, i.e., it has no patentable invention or creation, the author does not wish for personal publication, there is no confidential information.
Access Permission : Open Access