what has demanded from practical applications for collecting the big data. Therefore, to resolve the cost issues, a R2R printing foundry has been highly attracted because the flexible passive components (such as sensor electrodes, capacitors, and antenna) are able to integrate with their flexible active components (such as display, processor, [3] transponder, [4] analogto-digital converter (ADC), [5] operation amplifier [6]) through a R2R inline printing system. [7] However, although sensor electrodes, [8] capacitors, [9] antenna, [10] and thin film transistor (TFT) active matrix-based display [11] have been successfully printed via R2R printing method, they cannot integrate with flexible active components yet through the R2R inline printing system so far. The major reason in difficulty of inline integration of R2R printed passive components with the flexible active components was mainly originated from the incompatibility between printing and vacuum deposition techniques, employed in manufacturing those flexible active components. Although a printing process was incorporated with the vacuum deposition methods in fabricating those flexible active components, it was limited to fabricating only the semiconducting layers, [12] and lacked the scalability required for practical mass production. Thus, those hybrid vacuum deposition and printing processes cannot be incorporated into the R2R printing foundry. To establish the R2R printing foundry concept, the design rule that encompasses physical dimensions and electrical parameters of the fully printed devices should be first established. The design rule in a semiconductor fabrication plant-referred to as the foundry-is a compromised rule between circuit design engineers and process engineers to provide the geometry of an integrated circuit layout with an acceptable cost. However, unlike the Si-chip foundry, the printed devices' physical dimensions and electrical parameters are variable to the rheological parameters of the electronic inks, the web tension, printing speed, and overlay printing registration accuracy (OPRA) of employed R2R printer. Therefore, the design rule of the R2R printing foundry (Figure 1a) should be always comprising characteristics of both employed ink and R2R printer to prove that the R2R printed complementary metal-oxide-semiconductor (CMOS)-based active

spanning almost the entire range of commercial products in industry, agriculture, and medicine. That is why the development of roll-to-roll (R2R) printed passive RFID tags is extremely attractive, due to perceived cost reduction achievableindeed, this has been the driving force for the realization of the penny RFID tag for the ID and the authentication without incorporating any encryption engine. SuchThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/admt.201900935.Printed electronics has been received a great deal of attention in the last two decades with a primary focus being on the use of organic semiconductors for the inexpensive and flexible electronic devices. [1][2][3][4][5][6][7][8] Applications such as flexible displays and passive radio frequency identification (RFID) tags have been widely touted in this regard. In particular, the roll-to-roll (R2R) printed passive 13.56 MHz RFID tag has a very competitive advantage for ID and authentication to prevent counterfeits over the traditional Si-chip based one because the low cost is always the first priority to be considered to authenticate genuine products

Roll‐to‐roll (R2R) printed electronic devices have great advantages for developing large scale flexible and disposable devices when compared to current Si‐based technology. For practical realization of these advantages, however, R2R printed devices need to surmount device functionality limitations, most urgently high‐power dissipation and poor device stability. To resolve both imperative challenges at once, herein, an all R2R printed complementary metal‐oxide‐semiconductor (CMOS) 1‐bit code generator with spin‐coated multilayer encapsulation method is developed. In order to print CMOS devices by an all‐R2R gravure printing method, electrical amphoteric property of the single walled carbon nanotube (SWCNT) is utilized to fabricate both p‐type and n‐type SWCNT based thin film transistors (TFTs). In addition, printable encapsulating polymeric materials (CYTOP and FG‐3650) are developed to effectively prevent H2O permeation. The resulting CMOS 1‐bit code generator is able to continuously operate for 2 h under ambient conditions without any variation in output voltage and frequency.

We introduced a FGO–PVDF composite as an encapsulation layer to prove the reliability of PEDOT:PSS thermistors under high-humidity conditions to realize an NFC-enabled smart label for monitoring time-temperature history of a food item along the cold chain.

Current Si-based technologies have reached their intrinsic limits in meeting the demands of flexible electronics where free-form factors and low cost are critical for successful applications. For this reason, roll-to-roll (R2R) gravure printing has been considered a way to achieve the free-form factor and the low cost. However, the R2R gravure systems (servomechanism, electronic ink, printing process, and device design) could not integrate a number of thin-film transistors (TFTs) with small threshold voltage (V th) variations. Therefore, we designed a 4-bit code generator by combining one ring oscillator, six NAND gates, and one OR gate based on 37 p-type single-walled carbon nanotube (SWCNT) TFTs as a concept devices to test the R2R gravure system. First, ring oscillators with different physical dimensions were printed on a poly (ethylene terephthalate) roll using the R2R gravure. Then, we extracted important factors (channel length, channel width, and SWCNT network density) to optimize the V th variation and demonstrated a 4-bit code generator integrated with 37 p-type TFTs. This work will be further extended in the near future to develop R2R gravure printed near-field communication labels for smart packaging.

An all‐printed wireless triangle‐wave generator is needed to produce a printed wireless and disposable cyclic voltammetry (CV)‐based biosensor to detect redox‐active analytes. The generator should produce positive and negative potentials from the smartphone's near‐field‐communication (NFC) (13.56 MHz) carrier signal. However, the printed triangle‐wave generator that contains rectenna and a ring oscillator fails to wirelessly operate with a smartphone because the polarized (±) DC power from the NFC carrier signal of the smartphone could not be provided through the utilization of a printed Schottky diode. Herein, an n‐type indium gallium zinc oxide (IGZO)‐based ink is formulated to print the Schottky junction with a high work function of the printed electrode provided by in situ doping of printed poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) on Ag electrode. The printed IGZO‐based rectenna could wirelessly harvest polarized (±) DC 10 V from the smartphone to generate a triangle wave with positive and negative potentials through the printed ring oscillator.

As new authentic products are introduced into the market, counterfeiting has always been on the rise. In 2015, the global economic loss caused by counterfeiting is more than 1.7 trillion US dollars and has been increasing annually. Therefore, an inexpensive but efficient anti‐counterfeiting platform must be developed to end counterfeiting. Here, a wireless platform for the anti‐counterfeiting with an item‐tracking is developed by integrating printed four key‐device units, a 13.56 MHz rectenna (wireless power transmission), supercapacitors (power storage), 1‐bit code generator chip (logic code), and an electrophoretic based quick response code (memory). Our near‐field communication quick response code label platform is inexpensive and effective by utilizing blockchains and high throughput roll‐to‐roll printed devices. When practically applied, the near field communication quick response code label wirelessly operates through a near field communication carrier signal from a smartphone to demonstrate anti‐cloning and authentic item‐tracking through its interconnection with the blockchain.

The rheological properties of silver inks are analyzed, and the printing results are presented based on the inks and roll-to-roll printing speed. The shear viscosity, shear modulus, and extensional viscosity of the inks are measured using rotational and extensional rheometers. The inks exhibit the shear thinning power law fluids because the concentration of dispersed nanoparticles in the solvent is sufficiently low, which minimizes elasticity. After the inks are printed on a flexible substrate through gravure printing, the optical images, surface profiles, and electric resistances of the printed pattern are obtained. The width and height of the printed pattern change depending on the ink viscosity, whereas the printing speed does not significantly affect the widening. The drag-out tail is reduced at high ink viscosities and fast printing speeds, thereby improving the printed pattern quality in the roll-to-roll process. Based on the results obtained, we suggest ink and printing conditions that result in high printing quality for complicated printings, such as overlay printing registration accuracy, which imposes pattern widening and drag-out tails in printed patterns.