Flexible and Foldable Fully-Printed Carbon Black Conductive Nanostructures on Paper for High-Performance Electronic, Electrochemical, and Wearable Devices

Abstract

In this work, we demonstrate the first example of fully printed carbon nanomaterials on paper with unique features, aiming the fabrication of functional electronic and electrochemical devices. Bare and modified inks were prepared by combining carbon black and cellulose acetate to achieve high-performance conductive tracks with low sheet resistance. The carbon black tracks withstand extremely high folding cycles (>20 000 cycles), a new record-high with a response loss of less than 10%. The conductive tracks can also be used as 3D paper-based electrochemical cells with high heterogeneous rate constants, a feature that opens a myriad of electrochemical applications. As a relevant demonstrator, the conductive ink modified with Prussian-blue was electrochemically characterized proving to be very promising toward the detection of hydrogen peroxide at very low potentials. Moreover, carbon black circuits can be fully crumpled with negligible change in their electrical response. Fully printed motion and wearable sensors are additional examples where bioinspired microcracks are created on the conductive track. The wearable devices are capable of efficiently monitoring extremely low bending angles including human motions, fingers, and forearm. Here, to the best of our knowledge, the mechanical, electronic, and electrochemical performance of the proposed devices surpasses the most recent advances in paper-based devices.

Novel Eco‐Friendly Starch Paper for Use in Flexible, Transparent, and Disposable Organic Electronics

“…The research and development of flexible electronics using plastic substrates have received much attention over the past decade; however, flexible electronics using plastic substrates are not yet designed to be disposable because of the relatively expensive plastic materials and the environmental issues associated with their very slow break‐down . Recently, flexible electronics based on paper or cellulose have attracted considerable attention as a possible next‐generation technology capable of replacing current plastic‐based electronics . A wide range of applications, such as smart pixels, memory devices, printed circuits, electrowetting, batteries, photovoltaic devices, and touch sensors have been demonstrated on substrates composed of conventional paper or cellulose .…”

“…Despite their advantages as commercial flexible substrates, certain intrinsic problems associated with cellulose must be addressed before these substrates may be applied in the field of organic electronics. The major drawbacks associated with paper or cellulose substrates are their surface morphologies . In typical commercial‐grade printer paper made from plant fibers with diameters larger than 10 µm, the surface roughness can reach a few micrometers, around 10 3 to 10 4 times larger than the surface roughness values of Si/SiO 2 wafers or polymer substrates .…”

“…The major drawbacks associated with paper or cellulose substrates are their surface morphologies . In typical commercial‐grade printer paper made from plant fibers with diameters larger than 10 µm, the surface roughness can reach a few micrometers, around 10 3 to 10 4 times larger than the surface roughness values of Si/SiO 2 wafers or polymer substrates . To overcome the large surface roughness issue, planarization layers are introduced to reduce the surface feature size to the sub‐nanometer scale .…”

“…In typical commercial‐grade printer paper made from plant fibers with diameters larger than 10 µm, the surface roughness can reach a few micrometers, around 10 3 to 10 4 times larger than the surface roughness values of Si/SiO 2 wafers or polymer substrates . To overcome the large surface roughness issue, planarization layers are introduced to reduce the surface feature size to the sub‐nanometer scale . Alshareef and co‐workers group used a polymer planarization layer formed by a 40 µm thick polydimethylsiloxane layer on a banknote substrate to fabricate organic field‐effect transistor (OFET) memory devices with a ferroelectric layer .…”

Applications of Nanocellulose/Nanocarbon Composites: Focus on Biotechnology and Medicine

“…In addition, nanocellulose/nanocarbon composites are promising for biomedical applications, though these applications are less frequent than industrial applications. Biomedical applications include radical scavenging [34,92], photothermal ablation of pathogenic bacteria [93], photodynamic and combined chemophotothermal therapy against cancer [35,94], drug delivery [16,28,65,72,[95][96][97], biosensorics [31][32][33]63,66,71,91,[98][99][100][101][102][103][104], and particularly tissue engineering and wound dressings. Hybrid materials containing nanocellulose and nanocarbons stimulated the growth and osteogenic differentiation of human bone marrow mesenchymal stem cells [37,59].…”