Non-wrinkled, highly stretchable piezoelectric devices by electrohydrodynamic direct-writing

Abstract

Piezoelectric structures, in forms that allow mere in-surface deformations under large strains, are attractive for bio-integrated systems. Here, mechano-electrospinning (MES) is presented to direct-write straight nanofibers of polyvinylidene fluoride onto a prestrained poly(dimethylsiloxane) (PDMS) substrate, to position and polarize a piezoelectric nanofiber array in one-step. Wrinkled/non-wrinkled buckling modes are found when the substrates are released, and the morphology of the direct-written fiber proved the key to determine the buckling modes, which can be tuned precisely by MES parameters. The non-wrinkled, stretchable piezoelectric devices with a highly synchronized serpentine fiber array exhibit their in-surface deformation and stable piezoelectric performance up the failure strain of PDMS (∼110% in our study), which may be used as stretchable sensors and energy converters/providers.

A hierarchical computational model for stretchable interconnects with fractal-inspired designs

“…Recent advances in mechanics and materials for stretchable/flexible electronics Khang et al, 2006;Lacour et al, 2006;Jiang et al, 2007Jiang et al, , 2008Sekitani et al, 2009;Rogers et al, 2010;Huang et al, 2012;Yang and Lu, 2013;Duan et al, 2014) and optoelectronics Lipomi et al, 2011;Nelson et al, 2011) demonstrate that systems with high-performance semiconductor functionality can be realized in forms that allow extreme mechanical deformations, e.g., stretching like a rubber band, twisting like a rope, and bending like a sheet of paper. This class of technology creates many application opportunities that cannot be addressed with established technologies, ranging from "epidermal" health/wellness monitors (Kim et al, 2011b;Kaltenbrunner et al, 2013;Schwartz et al, 2013), to soft surgical instruments (Cotton et al, 2009;Yu et al, 2009;Viventi et al, 2010;Graudejus et al, 2012;Kim et al, 2012b), to eyeball-like digital cameras (Ko et al, 2008;Song et al, 2013), to sensitive robotic skins (Someya et al, 2004;Wagner et al, 2004;Mannsfeld et al, 2010;Lu et al, 2012).…”

Self-similar design for stretchable wireless LC strain sensors

“…Several factors should be considered in self-similar design, including the stretchability and stiffness of self-similar design, the controlling of deformation mode, the coupling relationship between deformation and electrical frequency, and the integration degree of coil. Additionally, we have proved that the cross-section dimension plays a critical role in controlling deformation mode, such as in-surface and out-of-surface buckling [9]. When the thickness becomes larger than the line width w line , the serpentine structure can avoid out-of-surface wrinkling.…”

“…There are many types of strain gauges existing, such as piezoresistive materials (Si [4], carbon nanotube [5], carbon-black [6]. ), and piezoelectric material (lead zirconate titanate (PZT) [7], zinc oxide (ZnO) [8], poly(vinylidene fluoride, PVDF) [9,10]) on a flexible or stretchable substrate. Continuous artificial skin strain monitoring is a consistent need for biological applications, e.g.…”

Fabricated Wavy Micro/Nanofiber via Auxiliary Electrodes in Near-Field Electrospinning

“…As a result, a helical, or wavy, fiber is found on the collector due to the small bending instability [9]. Yarin fibers appear [21]. Gu used a rotated electric field to fabricate twisted nanofibers for use in artificial muscles [22].…”