Conducting Shrinkable Nanocomposite Based on Au-Nanoparticle Implanted Plastic Sheet: Tunable Thermally Induced Surface Wrinkling

Abstract

A thermally shrinkable and conductive nanocomposite material is prepared by supersonic cluster beam implantation (SCBI) of neutral Au nanoparticles (Au NPs) into a commercially available thermo-retractable polystyrene (PS) sheet. Micronanowrinkling is obtained during shrinking, which is studied by means of SEM, TEM and AFM imaging. Characteristic periodicity is determined and correlated with nanoparticle implantation dose, which permits us to tune the topographic pattern. Remarkable differences emerged with respect to the well-known case of wrinkling of bilayer metal-polymer. Wrinkled composite surfaces are characterized by a peculiar multiscale structuring that promises potential technological applications in the field of catalytic surfaces, sensors, biointerfaces, and optics, among others.

Direct Comparison of Three Buckling-Based Methods to Measure the Elastic Modulus of Nanobiocomposite Thin Films

“…In uniaxial shrinking, the PS is clamped in one axis, which allows shrinking only in one direction and results in buckles that align with the free axis (Figure 4B). [16][17][18] In contrast, films buckled via SIEBIMM (Figure 4C) have a highly regular sinusoidal topology. However, cracks appeared for all films perpendicular to the wrinkles due to the expansion of the film in the opposite direction to compression (characteristic of positive Poisson's ratio materials), which is a common challenge for this method.…”

“…45 The scaling factor ( ) was calibrated by measuring characteristic wavelengths of thin films of sputtered gold with a known thickness and reported Poisson's ratio (0.42) 46 and elastic modulus (70 GPa). 16,46 For the film, ! =0.3 was used, which is in between the values reported for CNCs (0.28) and PEI (0.33) alone.…”

Cell Nanomechanics Based on Dielectric Elastomer Actuator Device

“…Adapted from Ref. [ 63 ] with permission. The Au NPs nanoparticles generated from the cluster source is accelerated by a carrier gas in a supersonic expansion and then focused by aerodynamic lens.…”

Topographical and Electrical Stimulation of Neuronal Cells through Microwrinkled Conducting Polymer Biointerfaces

“…The development of smart biointerfaces presenting multiple cues is desirable for tissue engineering applications, in order to trigger a variety of cellular responses, by delivering different heat-shrinkable polymer sheet ("substrate") is followed by an in-plane irreversible heat-induced shrinking of the substrate, which causes the stiffer skin to wrinkle upon the compressive in-plane forces exerted by the substrate. By mechanically constraining the shrinking along one direction, anisotropic patterns with microscale uniaxial wrinkles can be obtained, whose spatial periodicity (i.e., the average distance between wrinkle peaks) is tunable with the thickness of the skin, [30,31] as predicted by the mechanics of surface wrinkling. [32] As regards tissue engineering applications, uniaxially wrinkled patterns have been exploited for functional alignment of human embryonic stem cell-derived cardiomyocytes, trying to reproduce the native tissue topographical anisotropies.…”