An official website of the United States government
Abstract The demand for flexible printed electronics is growing fast, especially with the move toward the Internet of Things (IoT). These printed electrons are usually designed for short-term use, after which they are disposed of. The polymeric substrates used in printed electronics comprise the biggest portion of their non-biodegradable E-waste after their disposal. This paper demonstrates the feasibility of printing fully functional transient electronics on flexible, water-soluble, and biodegradable paper substrates using the dry printing approach. The in-situ generation and real-time sintering of silver nanoparticles at room temperature enables the fabrication of complex circuits on such water-soluble papers. A layout similar to an Arduino pro mini board is printed on both sides of a paper substrate with electrical interconnects. Various electrical components are then directly mounted to fabricate a complete, working paper Arduino circuit. Cyclic bending tests demonstrate the mechanical durability and reliability of printed paper circuits under repeated bending stress. The process uniquely achieves robust and complex printed electronics without thermal damage, and the water solubility tests successfully show rapid dissolution of the paper devices in water. Furthermore, the components detached during dissolution are collected and reused, demonstrating the recyclability of the process. Overall, this transformative manufacturing method establishes key technical capabilities to produce next-generation sustainable, green electronics and sensors using renewable materials.
more »
« less
Biodegradable elastomeric circuit boards from citric acid-based polyesters
Abstract Recyclable and biodegradable microelectronics, i.e., “green” electronics, are emerging as a viable solution to the global challenge of electronic waste. Specifically, flexible circuit boards represent a prime target for materials development and increasing the utility of green electronics in biomedical applications. Circuit board substrates and packaging are good dielectrics, mechanically and thermally robust, and are compatible with microfabrication processes. Poly(octamethylene maleate (anhydride) citrate) (POMaC) – a citric acid-based elastomer with tunable degradation and mechanical properties – presents a promising alternative for circuit board substrates and packaging. Here, we report the characterization of Elastomeric Circuit Boards (ECBs). Synthesis and processing conditions were optimized to achieve desired degradation and mechanical properties for production of stretchable circuits. ECB traces were characterized and exhibited sheet resistance of 0.599 Ω cm−2, crosstalk distance of <0.6 mm, and exhibited stable 0% strain resistances after 1000 strain cycles to 20%. Fabrication of single layer and encapsulated ECBs was demonstrated.
more »
« less
- Award ID(s):
- 2231012
- PAR ID:
- 10418087
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- npj Flexible Electronics
- Volume:
- 7
- Issue:
- 1
- ISSN:
- 2397-4621
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract 3D conformable electronic devices on freeform surfaces show superior performance to the conventional, planar ones. They represent a trend of future electronics and have witnessed exponential growth in various applications. However, their potential is largely limited by a lack of sophisticated fabrication techniques. To tackle this challenge, a new direct freeform laser (DFL) fabrication method enabled by a 5‐axis laser processing platform for directly fabricating 3D conformable electronics on targeted arbitrary surfaces is reported. Accordingly, representative laser‐induced graphene (LIG), metals, and metal oxides are successfully fabricated as high‐performance sensing and electrode materials from different material precursors on various types of substrates for applications in temperature/light/gas sensing, energy storage, and printed circuit board for circuit. Last but not the least, to demonstrate an application in smart homes, LIG‐based conformable strain sensors are fabricated and distributed in designated locations of an artificial tree. The distributed sensors have the capability of monitoring the wind speed and direction with the assistance of well‐trained machine‐learning models. This novel process will pave a new and general route to fabricating 3D conformable electronic devices, thus creating new opportunities in robotics, biomedical sensing, structural health, environmental monitoring, and Internet of Things applications.more » « less
-
Additive manufacturing has become a promising method for the fabrication of inexpensive, green, flexible electronics. Printed electronics on low-temperature substrates like paper are very appealing for the flexible hybrid electronics market for their use in disposable and biocompatible electronic applications and in areas like packaging, wearables, and consumer electronics. Plasma-jet printing uses a dielectric barrier discharge plasma to focus aerosolized nanoparticles onto a target substrate. The same plasma can be used to change the properties of the printed material and even sinter in situ. The technology can also be utilized in space and microgravity environments since the plasma-assisted deposition is independent of gravity. In this work, we show plasma voltage effect on deposition of gold nanoparticles and direct printing of flexible, conductive gold structures onto low-temperature paper substrates without the need for thermal or photonic post-processing. The effects of plasma parameters on the conductivity and flexible reliability of the printed films are studied, and a paper-based LED electrode is demonstrated.more » « less
-
Electrohydrodynamic Printed PEDOT:PSS/Graphene/PVA Circuits for Sustainable and Foldable ElectronicsAbstract The generation of electronic waste (e‐waste) poses a significant environmental challenge, necessitating strategies to extend electronics’ lifespan and incorporate eco‐friendly materials to enable their rapid degradation after disposal. Foldable electronics utilizing eco‐friendly materials offer enhanced durability during operation and degradability at the end of their life cycle. However, ensuring robust physical adhesion between electrodes/circuits and substrates during the folding process remains a challenge, leading to interface delamination and electronic failure. In this study, electrohydrodynamic (EHD) printing is employed as a cost‐effective method to fabricate the eco‐friendly foldable electronics by printing PEDOT:PSS/graphene composite circuits onto polyvinyl alcohol (PVA) films. The morphology and electrical properties of the printed patterns using inks with varying graphene and PEDOT:PSS weight ratios under different printing conditions are investigated. The foldability of the printed electronics is demonstrated, showing minimal resistance variation and stable electronic response even after four folds (16 layers) and hundreds of folding and unfolding cycles. Additionally, the application of printed PEDOT:PSS/graphene circuit is presented as a resistive temperature sensor for monitoring body temperature and respiration behavior. Furthermore, the transient features and degradation of the PEDOT:PSS/graphene/PVA based foldable electronics are explored, highlighting the potential promise as transient electronics in reducing electronic waste.more » « less
-
Abstract Resistors are basic yet essential circuit components that must be fabricated with high precision at low cost if they are to be viable for flexible electronic applications. Inkjet printing is one of many additive fabrication techniques utilized to realize this goal. In this work, a process termed self-aligned capillarity-assisted lithography for electronics (SCALE) was used to fabricate inkjet-printed resistors on flexible substrates. Capillary channels and reservoirs imprinted onto flexible substrates enabled precise control of resistor geometry and straightforward alignment of materials. More than 300 devices were fabricated using poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as the resistive material and silver as the electrode material. By varying PEDOT:PSS ink formulation and resistor geometry, resistances spanning from 170 Ω to 3.8 MΩ were achieved. Over 98% of devices were functional and the relative standard deviation in resistance ranged from 3% to 18% depending on resistor length and ink composition. The resistors showed no significant change in resistance after 10 000 cycles of bend testing at 1.6% surface tensile strain. In summary, this work demonstrated a fully roll-to-roll compatible process for inkjet printing resistors with superior properties.more » « less
