Tree root systems are often metaphors for strong foundations, strength, and resilience. They are also being used as prototypes for more substantial, adaptable electronics.
Researchers at Xi’an Jiaotong University have unveiled a new development in conformal electronics, addressing long-standing mechanical and thermal durability challenges. Their newly developed Template-Constrained Additive (TCA) printing technology, inspired by the robust structure of tree root systems, promises to significantly improve the fabrication of flexible electronic circuits. The findings were published on January 6, 2024, in the journal Microsystems & Nanoengineering.
a Schematic illustration of the analogy between a tree against the natural load and the circuits against the mechanical loads. b Fabrication process of the TCA printing. c SEM images of the section and top view of the printed MWCNTs and Ag circuits. d Demonstration of strong robustness of printed circuits. When the LED is lit using the printed serpentine circuit, it still lights up when the circuit is subjected to tweezers scraping, sandpaper grinding, and repeated hammering, respectively. Courtesy of Microsystems & Nanoengineering (Microsyst Nanoeng)
Conformal electronics, essential for applications such as smart skins, robotics, and integrated sensing systems, have historically been limited by their susceptibility to damage from mechanical stress and extreme temperatures. Traditional printing methods often produce circuits prone to tearing, cracking, and other forms of degradation, hindering their reliability and performance. Additionally, achieving high-resolution circuits with diverse materials has been a persistent challenge.
The TCA printing technology overcomes these obstacles by embedding adhesive into functional materials, creating a deep interlocking interface that significantly enhances the mechanical integrity of the circuits. This innovation allows the circuits to maintain their electrical performance even under harsh conditions, such as temperatures up to 350°C and intense mechanical wear. The method also achieves high-resolution printing with a precision of up to 300 nanometers. It supports a wide range of materials, including P(VDF-TrFE), multi-walled carbon nanotubes (MWCNTs), and silver nanoparticles (AgNPs).
One key advantage of TCA printing is its ability to produce multi-layered, self-aligned circuits, which addresses many of the limitations of conventional techniques. The study demonstrated the technology’s potential by fabricating conformal temperature and humidity sensors and ultra-thin energy storage systems. These applications highlight the versatility and transformative potential of TCA printing in advancing the field of flexible electronics.
“The TCA printing technology represents a major leap forward in the field of conformal electronics. By drawing inspiration from nature, we’ve developed a solution that not only enhances the durability of electronic circuits but also achieves remarkable precision and versatility. This makes it ideal for a wide range of applications, from wearables to advanced robotics.”
The implications of TCA printing are far-reaching. In autonomous vehicles, for example, the technology could enable the production of sensors capable of withstanding extreme environmental conditions. In robotics, it could improve the reliability and performance of electronic components integrated into robotic skins and joints. Beyond these applications, TCA printing opens new possibilities for integrating electronics into everyday objects, such as wearable devices and smart textiles. Its precision and flexibility also hold promise for advancements in aerospace and biomedical electronics, where durability and exactitude are critical.
The development of TCA printing marks a significant step forward in the evolution of conformal electronics. It offers a robust and versatile solution for creating durable, high-resolution circuits. As technology continues to evolve, it is poised to play a pivotal role in shaping the future of flexible electronics across various industries.
