CNT-based photopatternable nanocomposites with high electrical conductivity and optical transparency

Abstract

In this paper, a nanocomposite approach is introduced to provide both electrically conductive and optically transparent micropatterns on any flexible substrate employing photolithography-based microfabrication. The nanocomposite materials combine the highly directional nanoscopic networks and electrical conductivity of single-wall carbon nanotubes (SWNTs) with the photopatternability and optical transparency of SU-8 photoresist. The photopatternable nanocomposites have yielded high optical transparency of 90% and high electrical conductivity of 27.5 S m −1 with the minimal feature resolution of 10 μm. Additionally, an interesting nano-bridge phenomenon has been discovered during fabrication of the microscale features. Moreover, the photopatternable transparent conductive nanocomposite has demonstrated its application to biomedical sensing for exceptional adaptability and flexibility.

Smartphone-interfaced lab-on-a-chip devices for field-deployable enzyme-linked immunosorbent assay

“…52 Further increase in particle density creates a network of flow path that readily conducts current. 53 As expected, a higher conductivity has been achieved at a higher carbon ratio of the C-PDMS composition with the highest value of 15 S/m at 25%. There are several advantages of using C-PDMS as electrodes as opposed to conventional metal electrodes (e.g., platinum, gold, chromium, and titanium).…”

Fabrication of Circuits on Flexible Substrates Using Conductive SU-8 for Sensing Applications

“…Conductive SU-8 can be obtained by mixing silver nanoparticles [ 2 , 4 ], carbon black powder [ 5 , 6 ], single and multi-walled carbon nanotubes [ 7 , 8 , 9 ], graphene [ 10 ], conductive organic components [ 11 ], gold and even diamondoids [ 12 ]. Depending on the type of filler the mechanical, optical and electrical properties of the fabricated device are affected [ 12 ].…”

“…Some of the reported applications of conductive SU-8 include strain sensors [ 14 , 15 ], pressure sensors [ 9 ], biochips for electrografting [ 6 ], and as conductive material for inkjet printable applications [ 8 ]. Preliminary work involving circuit interconnection lines has only been reported in [ 16 ], where the conductive mixture of silver and SU-8 was deposited using a scraper and then back-side exposed through a quartz substrate; the patterned traces had a resistance variation from 800 Ω to 10 kΩ due to the inhomogeneity of the composite structures.…”

Topographical and Physicochemical Contrast in Photopatterned SU-8 Films for Microfabrication of Multilayer Structures

“…A growing number of polymer based microdevices, mainly applied in microfluidics, can be found in the literature [1][2][3][4][5][6]. The growing interest in polymer based MEMS [7] has driven the development of novel processes and protocols to control its mechanical [8][9][10], optical [11], magnetic [12][13][14], and electrical [15][16][17] properties. Also the surface chemistry [18], the resolution attainable during optical lithography [19], and the topographical features were intensively studied.…”