All-printed Electronics Research Articles

All-printed nanomembrane wireless bioelectronics using a biocompatible solderable graphene for multimodal human-machine interfaces

Recent advances in nanomaterials and nano-microfabrication have enabled the development of flexible wearable electronics. However, existing manufacturing methods still rely on a multi-step, error-prone complex process that requires a costly cleanroom facility. Here, we report a new class of additive nanomanufacturing of functional materials that enables a wireless, multilayered, seamlessly interconnected, and flexible hybrid electronic system. All-printed electronics, incorporating machine learning, offers multi-class and versatile human-machine interfaces. One of the key technological advancements is the use of a functionalized conductive graphene with enhanced biocompatibility, anti-oxidation, and solderability, which allows a wireless flexible circuit. The high-aspect ratio graphene offers gel-free, high-fidelity recording of muscle activities. The performance of the printed electronics is demonstrated by using real-time control of external systems via electromyograms. Anatomical study with deep learning-embedded electrophysiology mapping allows for an optimal selection of three channels to capture all finger motions with an accuracy of about 99% for seven classes.

All-Solution-Based Heterogeneous Material Formation for p-n Junction Diodes.

All-solution-based devices have potential as the next class of macroscale and multifunctional electronics on versatile amorphous substrates. Different methods and materials have been studied to control the formation of p-type and n-type semiconducting materials because forming active materials for transistors and sensors remains a challenge. This study proposes an approach for solution-based devices in which a p-n junction diode is fabricated using a solution-based InZnO thin film for the n-type semiconductor and a carbon nanotube network film for the p-type semiconductor. Additionally, the barrier height (∼160 meV) is extracted and a p-n junction diode on a plastic film is demonstrated. Although the performance requires further improvements by modifying the interfaces, this printing method may be an interesting approach for all-printed electronics, which can replace conventional Si electronics.

Flexible Pressure Sensor Driven by All-Printed Organic TFT Array Film

We have constructed a sheet-to-sheet (S2S) manufacturing line in order to prove the possibility and reality of production technologies and integrated processes of all-printed electronics devices[1,2,3]. In our automated and continuously operated manufacturing line, we operated the reverse offset printer for electrode pattern, digital inkjet printer for organic semiconductor layer, slit-die coater for insulator layer, and screen printer for electrode and inter-layer insulator. The average mobility of organic TFT is 0.7 cm2/Vs, average ON current is 5 uA with less than 10% sigma in A4 size area, and ON/OFF current ratio is ten of order 6. We have been acquiring successful results of TFT array flexible film in a reasonable high yield. These all-printed organic TFT array back-plane is applied to the flexible and light-weight pressure sensor which is driven in active matrix mode, and which is applied for a touch pad of writing with pressure grey scale or a commodity inventory system.

Direct Patterning by Inkjet Printing 3-Mercaptopropionic Capped Nano Silver Suspension

All-printed electronics as a mean of fast processing and achieving ultra-low-cost electronic devices has attracted great interest in recent years. Inkjet printing has excelled as the most promising technique by which the circuit components can be directly drawn on the specific area in one step. Furthermore, the low temperature reduction processes can be achieved by exploit the low-melting point characteristic of nanometallic particles. The inkjet printing technique to deposit silver nanoparticles (3.39±1.21 nm) capped by saturated 3-Mercaptopropionic acid onto silicon substrate was studied. The silver patterns were tested for its functionality as circuit components like conductor, resistor and capacitor. All components can be produced simply by thermal annealing of an inkjet printed patterns under an atmosphere of 90% N2-10% H2 at 300°C for 1 hr.

Inkjet deposited circuit components

All-printed electronics as a means of achieving ultra-low-cost electronic circuits has attracted great interest in recent years. Inkjet printing is one of the most promising techniques by which the circuit components can be ultimately drawn (i.e. printed) onto the substrate in one step. Here, the inkjet printing technique was used to chemically deposit silver nanoparticles (10–200 nm) simply by ejection of silver nitrate and reducing solutions onto different substrates such as paper, PET plastic film and textile fabrics. The silver patterns were tested for their functionality to work as circuit components like conductor, resistor, capacitor and inductor. Different levels of conductivity were achieved simply by changing the printing sequence, inks ratio and concentration. The highest level of conductivity achieved by an office thermal inkjet printer (300 dpi) was 5.54 × 105 S m−1 on paper. Inkjet deposited capacitors could exhibit a capacitance of more than 1.5 nF (parallel plate 45 × 45 mm2) and induction coils displayed an inductance of around 400 µH (planar coil 10 cm in diameter). Comparison of electronic performance of inkjet deposited components to the performance of conventionally etched items makes the technique highly promising for fabricating different printed electronic devices.

All-inkjet-printed flexible electronics fabrication on a polymer substrate by low-temperaturehigh-resolution selective laser sintering of metal nanoparticles

All-printed electronics is the key technology to ultra-low-cost, large-area electronics. As acritical step in this direction, we demonstrate that laser sintering of inkjet-printed metalnanoparticles enables low-temperature metal deposition as well as high-resolutionpatterning to overcome the resolution limitation of the current inkjet direct writingprocesses. To demonstrate this process combined with the implementation of air-stablecarboxylate-functionalized polythiophenes, high-resolution organic transistorswere fabricated in ambient pressure and room temperature without utilizing anyphotolithographic steps or requiring a vacuum deposition process. Local thermal control ofthe laser sintering process could minimize the heat-affected zone and the thermal damageto the substrate and further enhance the resolution of the process. This local nanoparticledeposition and energy coupling enable an environmentally friendly and cost-effectiveprocess as well as a low-temperature manufacturing sequence to realize large-area, flexibleelectronics on polymer substrates.

All-printed electronics and its applications: a status report

Mass printing technologies are promising technologies for the production of inexpensive electronics.In recent experiments, we have fabricated an integrated circuit solely by means of fast mass-printing methods without any steps breaking the production continuity. Our results clarified important issues that have to be taken into account when adapting printing technologies to the fabrication of electronics. Compatibility of materials and processes for the deposition of different layers on top of each other, uniformity and quality of layers with respect to electronic requirements as well as resolution and registration turned out to be challenging for the adaptation of printing technologies.In addition, first applications are already available, which rely on simplicity and inexpensive fabrication instead of high integration and high-end performance. Flexible cardboard-keyboards, chipless paper-identification systems as well as simple sensor systems can be regarded as applications that are paving the way for more sophisticated, printed electronics applications.

All-Printed Electronics: Materials, Devices, and Circuit Implications

Digital printing has garnered significant attention in recent years as a pathway to ultra-low-cost electronic systems. In particular, given the low viscosity requirements of inkjet printing, this has been a leading candidate technology for realization of allprinted electronic devices. We have developed inkjet-compatible materials for a full range of electronic materials, including printed conductors for interconnects and antennae, dielectrics for capacitors and transistors, and semiconductors for active devices. Using various combinations of nanoengineered particles and organic materials, we have realized fully printed transistors, diodes, and passive components with performance approaching the requirements of various applications including displays, sensors, and low-cost RFID tags. We review our materials technology, report on advanced devices fabricated using these materials, and discuss the implications of the same on the viability of fully-printed circuits.

High-quality inkjet-printed multilevel interconnects and inductive components on plastic for ultra-low-cost RFID applications

AbstractIn recent years, there has been tremendous interest in all-printed electronics as a means of achieving ultra-low-cost electronic circuits with uses in displays and disposable electronics applications such as RFID tags. While there have been a few demonstrations of printed organic transistors to date, there has been little work on the associated passive component and interconnection technologies required to enable the development of all-printed RFID circuits. In particular, low-resistance conductors are crucial to achieve the high-Q inductors necessary for RFID. Here, we demonstrate inkjetted nanoparticle-Au conductors on plastic with sheet resistances as low as 0.03 ohms/square. We describe the optimization of the jetting parameters, and their impact on final film morphology and electrical properties. We also demonstrate a bridging technology based on an inkjetted polyimide interlevel dielectric. Using this process, we demonstrate multilevel interconnect and passive component structures including conductor patterns, crossover bridges, and tapped planar spiral inductors. Together, these represent an important step towards the realization of all-printed RFID.