Simple and cost-effective method of highly conductive and elastic carbon nanotube/polydimethylsiloxane composite for wearable electronics

Abstract

The development of various flexible and stretchable materials has attracted interest for promising applications in biomedical engineering and electronics industries. This interest in wearable electronics, stretchable circuits, and flexible displays has created a demand for stable, easily manufactured, and cheap materials. However, the construction of flexible and elastic electronics, on which commercial electronic components can be mounted through simple and cost-effective processing, remains challenging. We have developed a nanocomposite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS) elastomer. To achieve uniform distributions of CNTs within the polymer, an optimized dispersion process was developed using isopropyl alcohol (IPA) and methyl-terminated PDMS in combination with ultrasonication. After vaporizing the IPA, various shapes and sizes can be easily created with the nanocomposite, depending on the mold. The material provides high flexibility, elasticity, and electrical conductivity without requiring a sandwich structure. It is also biocompatible and mechanically stable, as demonstrated by cytotoxicity assays and cyclic strain tests (over 10,000 times). We demonstrate the potential for the healthcare field through strain sensor, flexible electric circuits, and biopotential measurements such as EEG, ECG, and EMG. This simple and cost-effective fabrication method for CNT/PDMS composites provides a promising process and material for various applications of wearable electronics.

A water-resilient carbon nanotube based strain sensor for monitoring structural integrity

“…Carbon nanotubes represent the foundation for most of the conventional stretchable strain sensors 1,[8][9][10][11][12][13] , owing to performance characteristics which considerably exceed from known metal/metal oxides or organic semiconductors based sensors [14][15][16] , including large stretchability, high piezoresistivity and long term stability under mechanical strain. More precisely, single-walled carbon nanotubes (SWCNTs) possess one dimensional morphology with high aspect ratio to offer high internal piezoresistivity for use in strain sensors 17,18 .…”

Influence of Extracellular Mimicked Hierarchical Nano-Micro-Topography on the Bacteria/Abiotic Interface

“…Besides the fact that the first cycle corresponds to higher energy in the uncoated PDMS, it also clearly seems that the N1 coated sample has very low energy in each of the subsequent cycles, while PDMS shows a progressive decrease but always has higher values than the ones registered for the modified elastomer [35]. These results show that the presence of the PA thin film induces a more stable mechanical performance of the coating/substrate than the original PDMS [36].…”

Raman Spectroscopy as an Assay to Disentangle Zinc Oxide Carbon Nanotube Composites for Optimized Uric Acid Detection

“…Integrated areas of the Raman D band also tracked well as a function of sonication time with maximum current at 150 min, but had more scatter in the trend at other sonication times, likely due to sp 3 -hybridized carbon bond formation as a result of the creation of more sites to bind with ZnO during sonication. The degree of carbon nanotube disentanglement is directly quantified via integrated peak areas of the Raman G band, which denotes the amount of exposed sp 2 -hybridized carbon of the graphene sheet [45,46]. Since the sp 2 -hybridized carbon, represented by the G band, was never altered in the tethering of ZnO NPs, the G band intensity better represents the degree of MWNT disentanglement than that of the D band.…”