Stretchable multifunctional dielectric nanocomposites based on polydimethylsiloxane mixed with metal nanoparticles

Abstract

Next generation wearable electronics require stretchable dielectrics. There has been significant effort to characterize and improve the components of dielectric composites for use in these devices. In this work, a new stretchable dielectric material, composited by silver nanoparticles (Ag NPs), nickel nanoparticles (Ni NPs), and polydimethylsiloxane (PDMS), is prepared and characterized. The alternating arrays of Ag NPs groups and Ni NPs groups in the three-dimensional matrix of PDMS function as micro capacitors and prevent current percolation. Compared with PDMS alone, the alternating arrays exhibit a dielectric constant (k) that is increased by 1146% and can reach 35.13, with dielectric loss as low as 0.009. Slightly lower k and larger dielectric loss appear at high frequencies. The material exhibits negative temperature dependence, and the composition ratio affects the dielectric properties. The strain at break is 139.68% and the elastic modulus is as low as 3.57 kPa. By controlling the type, size and dispersion of metal nanoparticles in PDMS matrix, a parallel-plate capacitor with constant capacitance is achieved, demonstrating the dependence of the dielectric constant on the applied strain. Moreover, by replacing the parallel plates with cylindrical fibers, a capacitive strain sensor was demonstrated. After hundreds of stretching-releasing cycles, the dielectrics work normally. The excellent properties of this material suggest its significant potential for use in wearable electronics.

Porous Polydimethylsiloxane Elastomer Hybrid with Zinc Oxide Nanowire for Wearable, Wide-Range, and Low Detection Limit Capacitive Pressure Sensor

“…Unlike conventional composites or a sole type of material, polymer-based nanocomposites may offer considerable enhancement in thermal, electrical, optical, chemical, or mechanical properties. Among them, a variety of nanostructures with highly conductive [14][15][16], dielectric [17][18][19], piezoelectric [20][21][22], triboelectric [23][24][25], photo-responsive [26][27][28], or stress-sensitive [10,[29][30][31] properties have been studied for flexible pressure sensors because of their potential in amplifying stress/strain sensing capability for human motion detection, health diagnosis, and electronic skin.…”

Highly stretchable and sensitive strain sensors with ginkgo-like sandwich architectures

“…10 and 11) while several studies have also demonstrated conductors with a stretchability of more than 500%, or even as high as 2000% that however have not been used to sense strain. [12][13][14][15] While a large number of previous studies have achieved a stretchability of approximately 300% and a sensitivity of approximately 50, more recent studies have found it difficult to further improve the overall strain sensor performance. [16][17][18][19][20][21][22][23][24] The use of nanomaterials and deformable structures are the two most common strategies for obtaining stretchable electronics.…”

“…Strain sensors play an important role in these fields and their performance is mainly measured by sensitivity and stretchability [9] . To date, some sensors have achieved sensitivity above 10 3 under tensile strain of less than 8% [10][11] while several studies have also demonstrated conductors with a stretchability of more than 500%, or even as high as 2000% that however have not been used to sense strain [12][13][14][15] . While a large number of previous studies have achieved a stretchability of approximately 300% and a sensitivity of approximately 50, more recent studies have found it difficult to further improve the overall strain sensor performance [16][17][18][19][20][21][22][23][24] .…”

Gold Nanoparticles as Effective ion Traps in Poly(dimethylsiloxane) Cross-Linked by Metal-Ligand Coordination

“…Rajitha and Dash proposed a PDMS/reduced graphene oxide composite that preserved optical transparency while increasing the permittivity up to 38 [ 14 ]. The addition of ceramic such as BaTiO 3 [ 15 ], SrTiO 3 [ 16 ], as well as metallic [ 17 ] nanoparticles also caused an increase in permittivity of PDMS-based composites. Moreover, on a nanometric scale, they exhibited unusual optical and electrical properties due to quantum confinement.…”

“…The authors observed a remarkable enhancement of permittivity, reaching up to 900, as well as dielectric loss equal to 0.14. It was Feng et al, in turn, who proposed a composite of silver and nickel nanoparticles embedded in the PDMS matrix—a system characterized by very low dielectric loss—0.009 for 1 MHz at room temperature and a maximum dielectric permittivity of 35 [ 17 ].…”