Screen Printed Reflective Electrochromic Displays for Paper and Other Opaque Substrates

Abstract

Paper electronics is a viable alternative to traditional electronics, leading to more sustainable electronics. Many challenges still require solutions before paper electronics become mainstream.Here, we present a solution to enable the manufacturing of reflective allprinted organic electrochromic displays (OECDs) on paper substrates; devices that are usually printed on transparent substrates, for example, plastics. In order to operate on opaque paper substrates, an architecture for reversely printed OECDs (rOECDs) is developed. In this architecture, the electrochromic layer is printed as the last functional layer and can therefore be viewed from the print side. Square shaped 1 cm 2 rOECDs are successfully screen printed on paper, with a high manufacturing yield exceeding 99%, switching times <3 s and high color contrast (ΔE* > 27). Approximately 60% of the color is retained after 15 min in open-circuit mode. Compared to the conventional screen printed OECD architectures, the rOECDs recover approximately three times faster from storage in a dry environment, which is particularly important in systems where storage in low humidity atmosphere is required, for example, in many biosensing applications. Finally, a more complex rOECD with 9 individually addressable segments is successfully screen printed and demonstrated.

Fully Screen‐Printed Stretchable Organic Electrochemical Transistors

“…The initial resistance of the S V4 prints increased when printed on top of the electrolyte (Figure 1h), likely due to solvents in the PEDOT:PSS partially solvating the electrolyte layer. [ 45 ] However, the relative increase in resistance during cycling decreased in comparison to prints on TPU, despite some crack formation on top of the electrolyte—S V4 forms cracks during strain even when printed on TPU (Figure 1i,j). [ 44 ] One should note that successful printing of S V4 ink on top of the electrolyte required drying of the electrolyte prints immediately prior to S V4 printing.…”

All‐Printed Electrochromic Stickers

“…In fact, the textile sticker showed slightly higher contrast than the PET control (ΔE* 25 vs 24, values can be viewed in Table S2, Supporting Information) and the retention time (optical memory) experiment presented in Figure 1D shows similar behavior for all the evaluated samples as well as similar behavior to data reported previously. [18] With the success of the rECDs on sticker substrates, the stickers were then removed from their release liners and placed on planar and curved surfaces. This experiment highlights the advantage a sticker substrate has over conventional non-adhesive substrates.…”

“…In fact, the textile sticker showed slightly higher contrast than the PET control (Δ E * 25 vs 24, values can be viewed in Table S2, Supporting Information) and the retention time (optical memory) experiment presented in Figure 1D shows similar behavior for all the evaluated samples as well as similar behavior to data reported previously. [ 18 ]…”

“…This technology is only possible by using an adapted vertical electrochromic structure reported recently, which allows opaque substrates to be utilized. [ 18 ] This manuscript reported the conventional vertical electrochromic architecture order in reverse, thereby having the electrochromic PEDOT:PSS layer visible as the top layer. Within this manuscript, we extend this technology to sticker substrates for ease of transfer onto curved surfaces.…”

Laser-Ablated Transmutation of Bulk TiO2 into Nanospheres onto a Clad-Polished Optical Fiber for Room-Temperature Gas Sensing

“…Nanostructured metal oxide semiconductors (MOSs) have been employed by researchers due to their wide applicability in sectors such as automobile, marine, textile, metal extraction, mining, medicine, oil, natural gas industries, etc. ,,, There are burgeoning studies on transition metal oxide semiconductors with d 0 and d 10 electronic configurations, particularly for the detection of simple volatile organic compound (VOC) gases due to properties such as enhanced sensitivity, selectivity, stability, and quick dynamic response. ,− Titanium dioxide (TiO 2 ) with the d 0 configuration is a popular wide band gap semiconductor to have eminent gas sensing properties due to many meticulous advantages such as greater response, highest stability at ambient conditions, low cost, and non-toxicity. − TiO 2 is particularly attractive for gas sensors because it has a lower cross-sensitivity to humidity than that of other metal oxides …”