Carbon Nanotube Active-Matrix Backplanes for Conformal Electronics and Sensors

Abstract

In this paper, we report a promising approach for fabricating large-scale flexible and stretchable electronics using a semiconductor-enriched carbon nanotube solution. Uniform semiconducting nanotube networks with superb electrical properties (mobility of ∼20 cm2 V(-1) s(-1) and ION/IOFF of ∼10(4)) are obtained on polyimide substrates. The substrate is made stretchable by laser cutting a honeycomb mesh structure, which combined with nanotube-network transistors enables highly robust conformal electronic devices with minimal device-to-device stochastic variations. The utility of this device concept is demonstrated by fabricating an active-matrix backplane (12×8 pixels, physical size of 6×4 cm2) for pressure mapping using a pressure sensitive rubber as the sensor element.

User-interactive electronic skin for instantaneous pressure visualization

“…In addition, the active-matrix backplane also offers excellent flexibility without degradation to the device performance as shown in the Supplementary Fig. S3) and our previous studies 9,17 . The characteristics of the standalone OLEDs are also characterized.…”

“…The transistors exhibit a uniform performance in terms of on-current (I on ), transconductance (g m ) and mobility (Supplementary Fig. S2), which is attributed to the uniform nanotube networks obtained using the assembly method applied in this work 9,17 . The mean and standard deviation values for I on , g m and field-effect mobility are 3.6 ± 0.3 mA, 1.0 ± 0.1 mS and 20 ± 2 cm 2 V −1 s −1 , respectively.…”

“…Next, the wafer is processed by conventional microfabrication steps, such as photolithography and metallization, to pattern and deposit the various layers. After the completion of fabrication, the polyimide layer with the devices on top was delaminated from the handling wafer 5,9,17 , resulting in a highly bendable systemon-plastic. The step-by-step details of the fabrication process are presented in the Methods and Supplementary Fig.…”

Design of Surfactant–Substrate Interactions for Roll-to-Roll Assembly of Carbon Nanotubes for Thin-Film Transistors

“…The peak mobility from a parallel plate model is extracted as 2 cm 2 / V s (Supporting Information), which is respectable for a R2R process scheme, but lower than those obtained by solution casting on smooth surfaces. 39,61 We speculate that the roughness of the PET film reduces the density of the assembled SWCNTs. For higher device performance, contact metals, deposition process, dielectric layer, etc., need to be further optimized.…”

Recent Progress in Electronic Skin

“…The first method directly bonds thin conductive materials that have low Young's moduli to a rubber/elastic substrate, such as poly(dimethylsiloxane) (PDMS). Geometrical patterning and device designs, e.g., net‐shaped structures,41 were also employed to further enhance stretchability and adaptability ( Figure 3 a). Rogers and co‐workers has pioneered many strategies for the adherence of conventional inorganic materials with excellent electronic performance and rigidity to elastomeric soft substrates 42.…”