Science and Technology Daily reported on October 22 that the Massachusetts Institute of Technology team has made an important progress in the field of electronic manufacturing: they use full 3D printing technology to produce active electronic devices that do not require semiconductor materials. The results, published in the journal Virtual & Physical Prototypes, offer a new direction for the electronics manufacturing industry. These components are printed using low-cost and biodegradable materials using 3D printers. Although the performance of these devices has not yet reached the level of conventional semiconductor transistors, they have been able to perform some basic control tasks, such as adjusting the rotational speed of an electric motor. This technology consumes less energy and produces less waste, reducing manufacturing costs and reducing environmental impact.
In the experiments, the researchers found that polymer filaments containing copper nanoparticles exhibited a significant increase in resistance when passing through a large current, and that the resistance quickly returned to its original state after a power failure. This property allows the material to be used as a switching element, which functions similarly to a transistor in semiconductors. The research team tested a variety of polymer filaments of different doped materials, including carbon, carbon nanotubes and graphene, but only the filaments containing copper nanoparticles showed the ability to self-reset. The team speculated that the thermal effect caused by the electric current may cause the copper particles to diffuse, thereby increasing the electrical resistance. After cooling, the copper particles re-aggregate and the resistance decreases. At the same time, the transition between the crystalline and amorphous states of the polymer matrix may also have an effect on the change in electrical resistance. Based on this finding, the research team developed a novel logic gate consisting of copper-doped polymer filaments that controls changes in resistance by adjusting the input voltage. In addition, by adding other functional particles to the polymer filaments, more complex and diverse applications can be realized.
The results of this research not only demonstrate the potential of small businesses to produce simple smart hardware autonomously in the future, but also provide new manufacturing methods for the basic units of digital logic circuits such as logic gates. These basic units, such as "and", "or", "not", etc., can be composed of any complex logic circuit through different circuit configurations. Although the performance of these 3D-printed active electronic device components is not yet comparable to that of transistors, they already have basic control functions and are expected to be an alternative to transistors due to their low cost and low environmental impact.