3. Results and discussion
3.1. System reconfiguration of electronic devices
A semi-dried membrane of NFC mixed with appropriate
plasticizers exhibits gel-like behavior when it comes to
appearance and physical hardness. This property is
partially remained in the fully dried state and hence a
self-supporting film can be obtained thanks to the strong
scaffold functionality of NFC, which originates from hydrogen bonds and/or ionic bonds inside the polymer matrix
(not investigated further in this report), see Fig. 1 . The
resulting self-supporting composite films containing EC
or electrolyte materials can weakly adhere to other solid
functional substrate surfaces by simple lamination. Thanks
to its weak adhering property the film can also be detached
(here called ‘‘delaminated’’) from a substrate while maintaining shape and functionality. This finally results in an
extremely high degree of freedom to construct, disassemble and reconstruct multilayered printed electronic components. For example, in this report, NFC membranes
hybridized with PEDOT:PSS (labeled as P:PSS-NFC) are
stacked onto NFC membranes hybridized with polyelectrolyte and white TiO2 pigment (denoted opaque Plyte-NFC)
by hand, and a vertical symmetric electrochromic display
(ECD) is established by that another layer of P:PSS-NFC is
laminated on the other side of the Plyte-NFC.
Additionally, two other display architectures can also be
prepared by simple lamination. A lateral symmetric ECD is
constructed by the lamination of two separated P:PSS-NFC
on the same side of the Plyte-NFC, where the two P:PSSNFC are physically isolated. A vertical non-symmetric
ECD is instead made from a drop-cast PANI layer on top
of a Plyte-NFC (Plyte-NFC-PANI) and lamination of P:PSSNFC on the opposite surface of the Plyte-NFC layer. These
three ECD structures are drawn in Fig. 2(a–c).
Upon delamination of the vertical symmetric ECD, one
of the P:PSS-NFC layers is delaminated and removed from
the other two layers, and the remaining bilayer can instead
be laminated onto another functional surface in order to
serve as e.g. the electrolyte and the ECD pixel electrode
or the electrolyte and the gate electrode of an electrochemical transistor (ECT). This whole process, consisting of lamination, delamination and re-lamination, is here denoted
‘‘system reconfiguration’’. Additionally, the NFC-based
functional films typically are very robust and can be cut
by scissors, folded or bended, hence, they have an appearance similar to the sticky notes used in scrapbooks or sticker books