Novel Surfactant-Induced MWCNTs/PDMS-Based Nanocomposites for Tactile Sensing Applications

Abstract

The paper presents the use of surfactant-induced MWCNTs/PDMS-based nanocomposites for tactile sensing applications. The significance of nanocomposites-based sensors has constantly been growing due to their enhanced electromechanical characteristics. As a result of the simplified customization for their target applications, research is ongoing to determine the quality and quantity of the precursor materials that are involved in the fabrication of nanocomposites. Although a significant amount of work has been done to develop a wide range of nanocomposite-based prototypes, they still require optimization when mixed with polydimethylsiloxane (PDMS) matrices. Multi-Walled Carbon Nanotubes (MWCNTs) are one of the pioneering materials used in multifunctional sensing applications due to their high yield, excellent electrical conductivity and mechanical properties, and high structural integrity. Among the other carbon allotropes used to form nanocomposites, MWCNTs have been widely studied due to their enhanced bonding with the polymer matrix, highly densified sampling, and even surfacing throughout the composites. This paper highlights the development, characterization and implementation of surfactant-added MWCNTs/PDMS-based nanocomposites. The prototypes consisted of an optimized amount of sodium dodecyl sulfonate (SDS) and MWCNTs mixed as nanofillers in the PDMS matrix. The results have been promising in terms of their mechanical behaviour as they responded well to a maximum strain of 40%. Stable and repeatable output was obtained with a response time of 1 millisecond. The Young’s Modulus of the sensors was 2.06 MPa. The utilization of the prototypes for low-pressure tactile sensing applications is also shown here.

A Microfluidic Chip-Based Automated System for Whole-Course Monitoring the Drug Responses of Organoids

“…Microfluidic chips have the ability to automatically culture PDOs at the microenvironmental level, enhancing the stability of PDO models and the precision of drug incorporation. − Furthermore, polydimethylsiloxane (PDMS), a fundamental material employed in microfluidic chip fabrication, exhibits notable characteristics such as high biocompatibility, elasticity, transparency, breathability, and hydrophilicity (after modification). , These inherent properties of PDMS play a pivotal role in facilitating the culture and proliferation of living cells within the microfluidic environment. , Representative PDO morphologies and volume calculation for both on-chip and off-chip cultures are presented (Figure S1), illustrating that the PDMS material for microfluidic chip had no influence on the cell viability of PDO. Just as many other clinically applied equipment, all analysis procedures should be performed in a single chip to meet the strict limitation of tissue sample amount by eliminating cell transfer between different operations.…”

“…35−38 Furthermore, polydimethylsiloxane (PDMS), a fundamental material employed in microfluidic chip fabrication, exhibits notable characteristics such as high biocompatibility, elasticity, transparency, breathability, and hydrophilicity (after modification). 39,40 These inherent properties of PDMS play a pivotal role in facilitating the culture and proliferation of living cells within the microfluidic environment. 41,42 Representative PDO morphologies and volume calculation for both on-chip and off-chip cultures are presented (Figure S1), illustrating that the PDMS material for microfluidic chip had no influence on the cell viability of PDO.…”

Amphiphilic Silicones for the Facile Dispersion of Carbon Nanotubes and Formation of Soft Skin Electrodes

“…27 As the CNT dispersion is enhanced, percolation clusters form, and electrical signals can flow through an otherwise nonconducting material such as silicone. 30,31 However, dispersion of CNTs in silicones using surfactants such as dodecylbenzenesulfonic acid (DBSA), 28,32 cetyltrimethylammonium bromide (CTAB), 28,32 sodium dodecyl sulfonate (SDS), 33 and Disperbyk-191 (an acrylate copolymer) 34 requires not only the addition of solvents but prior surface modification of CNTs or extensive mixing procedures. Furthermore, the lack of surfactant compatibility with the silicone can also lead to phase separation of the surfactant and subsequent diminished mechanical properties.…”

“…Additionally, silicones are known for their high gas and water vapor permeability as well as their chemical stability, making them ideal for long-term use. , Dispersion of CNTs in silicones has been evaluated with the aforementioned techniques, − as well as with the use of surfactants. , Above the critical micelle concentration (CMC), the surfactants form self-assembled micellular structures that separate CNT aggregates via an excluded volume effect . As the CNT dispersion is enhanced, percolation clusters form, and electrical signals can flow through an otherwise nonconducting material such as silicone. , However, dispersion of CNTs in silicones using surfactants such as dodecylbenzenesulfonic acid (DBSA), , cetyltrimethylammonium bromide (CTAB), , sodium dodecyl sulfonate (SDS), and Disperbyk-191 (an acrylate copolymer) requires not only the addition of solvents but prior surface modification of CNTs or extensive mixing procedures. Furthermore, the lack of surfactant compatibility with the silicone can also lead to phase separation of the surfactant and subsequent diminished mechanical properties …”

Special Issue: Advanced Science and Technology of Polymer Matrix Nanomaterials

“…The subjects of this issue aim to uncover the potential improvements in the synthesis, properties and performance of polymer matrix nanomaterials regarding new preparation techniques, sensing, electromagnetic interference shielding, self-healing, microwave absorption, switching, structural modulation, mechanical reinforcement, drug delivery and other biomedical applications etc. [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”