Nanomechanics of Materials used in Flexible Electronics

Organic semiconductors are multifunctional soft electronic materials that play an impactful role in the flexible electronics industry. Their use spans printed electronic circuits, large area displays, flexible solar energy harvesters, and implantable bioelectronics. For their competitive optical, electronic, thermoelectric, and spin-based properties, these soft electronic materials attract significant academic engagement, seeding new technologies for the future. ^{[1, 2, 3]}<br/><br/>Although macroscopic flexibility on the centimetre to metre scale is a unique selling point for organic semiconductor technology, not much is known about their mechanical properties on the nanoscale. Quantification of these nanomechanical properties, together with an understanding of nanoscale stiffness tunability and homogenisation, holds significant potential for fundamental and applied science. ^{[4, 5]}<br/><br/>During the last decade, the development of high precision atomic force microscopes has made it possible to quantify the mechanical properties of organic polymers on the scale of a few polymer chains. Techniques such as higher eigen mode imaging make it possible to visualise molecular ordering on the nanoscale under ambient conditions with ease. These techniques allow one to correlate molecular ordering with the stiffness that such ordering manifests.<br/><br/>In this talk, the science and technology of precision nanoscale measurement of mechanics will be spotlight. The interrelation between molecular organisation and nanomechanical properties in high-performance polymers used for organic electronics will be shown. ^{[6, 7]} A quantification of differences in strain within organic nanocrystal polymorphs will also be demonstrated. The measurement techniques demonstrated in this talk are extendable to a wide variety of multifunctional materials with a broad range of elastic properties and have significant use in both academia and industry.<br/><br/>[1] D. Venkateshvaran, M. Nikolka <i>et al.</i>, Nature <b>515</b>, 384–388 (2014)<br/>[2] S. J. Wang, D. Venkateshvaran <i>et al.</i>, Nature Electronics <b>2</b>, 98–107 (2019)<br/>[3] P. Skalski, O. Zadvorna <i>et al.</i>, Physical Review Materials<b> 6</b>, 024601 (2021)<br/>[4]<b> </b>L. Ouyang, C. Kuo <i>et al.</i>, J. Mater. Chem. B<b> 3</b>, 5010 (2015)<br/>[5] C. D. Gerardo <i>et al.</i>, Microsystems and Nanoengineering <b>4,</b> 19 (2018)<br/>[6] V. Panchal, I. Dobryden … D. Venkateshvaran, Advanced Electronic Materials<b> 8</b>, 2101019 (2022)<br/>[7] I. Dobryden, V. V. Korolkov … D. Venkateshvaran, Nature Communications <b>13</b>, 3076 (2022)