According to a recent report on the official website of the German Electron Synchrotron Institute (DESY), the institution and the University of Hamburg have developed a process suitable for 3D printing technology, which can be used to manufacture transparent and mechanically flexible electronic circuits.

 

Background

Flexible electronics is a very popular emerging technology in recent years. Different from the rigid and dull impression that traditional electronic devices give us, flexible electronic products can work normally under a certain range of deformation (bending, folding, twisting, compression or stretching).

 

 

At present, flexible electronics has become one of the research hotspots in interdisciplinary fields, covering organic electronics, plastic electronics, bioelectronics, nanoelectronics, printed electronics and other fields, and its products include RFID, flexible display, OLED display And lighting, flexible sensors, flexible photovoltaics, flexible logic and storage devices, flexible batteries, wearable devices, electronic skin, etc.

 

 

Innovation

Recently, the cooperation between the University of Hamburg and the German Electron Synchrotron Institute (DESY) has developed a process suitable for 3D printing technology, which can be used to manufacture transparent and mechanically flexible electronic circuits. These electronic devices consist of networks of silver nanowires that can be printed in suspension and embedded in various flexible and transparent plastics (polymers).

This technology could open up new applications such as printing light-emitting diodes, solar Batteries or tools with integrated circuits. The researchers are currently demonstrating the potential of their process to make flexible capacitors, among other products.

 

Technology

Michael Rübhausen from the Center for Free-Electron Laser Science (CFEL), a joint venture between DESY, the University of Hamburg and the Max Planck Society, said: Applied Design 3D Printable Polymers. With our new approach, we want to integrate electronics into existing building blocks and improve the volume and weight of the components.”

The professor of physics at the University of Hamburg led the project together with DESY researcher Stephan Roth, professor at the KTH Royal Institute of Technology in Stockholm. Using bright light from the DESY research light source PETRA III and other measurement methods, the team precisely analyzed the properties of the nanowires in the polymer.

"At the heart of this technology are silver nanowires, which form a conductive network," Gehler explained. Typically, the silver wires are tens of nanometers thick and 10 to 20 micrometers long. Detailed X-ray analysis revealed that the structure of the nanowires in the polymer did not change, but the conductivity of the mesh was boosted by extrusion of the polymer, which shrank during curing.

The silver nanowires are applied in suspension on the substrate and dried. Ross, head of measuring station P03 at the DESY X-ray light source PETRA III (where the X-ray research takes place), explains: "Due to cost factors, the goal is to achieve the highest conductivity with as few nanowires as possible. This will also improve the performance of the material. In this way, layer by layer, they create conductive paths or surfaces.” A flexible polymer is applied to the conductive traces, which are then covered with conductive traces and contacts. Depending on the geometry and the materials used, various conductive elements can be printed in this way.

In this paper, the researchers fabricated a flexible capacitor. "In the laboratory, we carry out the individual work steps in the layering process, but in practice they are then completely transferred to the 3D printer," explains Lübhausen. "However, traditional 3D printing techniques It is usually optimized for individual printing inks. For this, it is also necessary to further develop conventional 3D printing techniques. In inkjet-based processes, the printing nozzles are blocked by nanostructures.”