Inkjet Printing of Conjugated Polymer Precursors on Paper Substrates for Colorimetric Sensing and Flexible Electrothermochromic Display

Abstract

Inkjet-printable aqueous suspensions of conjugated polymer precursors are developed for fabrication of patterned color images on paper substrates. Printing of a diacetylene (DA)-surfactant composite ink on unmodified paper and photopaper, as well as on a banknote, enables generation of latent images that are transformed to blue-colored polydiacetylene (PDA) structures by UV irradiation. Both irreversible and reversible thermochromism with the PDA printed images are demonstrated and applied to flexible and disposable sensors and to displays.

Hydrochromic molecular switches for water-jet rewritable paper

“…1b). To our pleasant surprise, most of oxazolidines (1)(2)(3)(4)(5) and oxazines (11)(12) have favourable hydrochromic properties with good colour intensity and stability at ambient conditions, while the well-studied conventional spiropyrans (14-18) hardly show hydrochromism under the same conditions, and their OFs can only be observed either at elevated temperature or in the dark with poor colour intensity (more than one order of magnitude lower) (see Supplementary Fig. 1 and Supplementary Discussion).…”

“…Current digital prints do not de-ink and recycle well, and this creates huge problems of solid waste and environmental pollution. Ink-free printing and rewritable paper [2][3][4][5][6][7][8][9][10] have recently attracted attention owing to their potential benefits to forest conservation 11 , waste paper reduction and cutting down the cost of office printing. Incorporating switchable dyes in paper as an imaging layer represents an ideal economic approach towards rewritable paper.…”

A skin-like stretchable colorimetric temperature sensor

“…The change in color, absorption and luminescence can be directly visualized by the naked eye and captured by the optical detectors. In this aspect, polydiacetylene (PDA) appears to be a favorable choice [27][28][29][30][31]. PDA was selected as the thermo-responsive element for this platform owing to their responsive color transition (blue-to-red) and fluorescence change (non-tored) when subjected to thermal stimulus.…”

Interfacial Nano-Mechanical Properties of Copper Joints Bonded with Silver Nanopaste near Room Temperature

“…The interconnection of components with metallurgical bonds is a key requirement for micro/nano-electronic devices since conductive joints are needed in transistors, 13) sensors, 4,5) solar cells 6,7) and display units. 810) Commonly used lead-free soldering processes reach 200 to 300°C to obtain conductive joints, 11,12) which severely restricts joining for heat-sensitive components in flexible electronic devices.…”