In today’s world, the demand for on-demand sensor fabrication is increasing, particularly in settings with limited resources like agriculture, healthcare, disaster areas, and space missions. Researchers are now focusing on sustainable designs for disposable devices that can create low-cost, resource-efficient internet of things (IoT) sensors. However, current methods for 3D device fabrication face challenges in terms of portability, limiting their on-site usability.
A team of researchers led by Associate Professor Hiroki Shigemune from Shibaura Institute of Technology, Japan, alongside Dr. Yuhi Watanabe and Dr. Atsushi Matsushita, has introduced a new portable, multimaterial printer for on-site production of origami devices using electrowetting on dielectric (EWOD) technology. This digital microfluidic method enables precise control and manipulation of liquid droplets on a surface without the need for external valves or pumps. Their findings have been published in the journal ACS Applied Materials & Interfaces.
“We have developed a compact, palm-sized printer that utilizes EWOD technology to independently manage and print both conductive and insulating liquids. By depositing functional inks onto paper substrates with electrical signals, this system enables the rapid fabrication of origami devices on-site,” explains Dr. Shigemune.
The researchers have optimized printing conditions for both structural and electrode inks separately and in combination, without compromising functionality. They applied this technique to create an origami stretchable strain sensor and a respiration sensor. The strain sensor demonstrated stable performance even after 1,000 cycles of deformation, while the respiration sensor exhibited consistent signal responses during breath detection. The system’s durability, flexibility, and environmental compatibility highlight its potential for various applications.
Dr. Shigemune envisions the system’s use in producing custom sensors and devices tailored to specific needs in portable IoT device manufacturing platforms, particularly in agriculture and healthcare settings. The simplicity of the system, consisting of paper, ink, and a small-scale control device, allows for easy transport and storage, making it ideal for off-grid environments and emergency situations.
The portable printer shows promise for real-world applications, such as creating sensor-integrated smart agricultural packaging to enhance fruit quality and developing wearable health monitoring devices for respiratory and movement tracking. Dr. Shigemune concludes that this novel fabrication approach contributes to sustainable and flexible manufacturing practices in smart agriculture, medical IoT, and personalized healthcare.
