A high gauge-factor wearable strain sensor array via 3D printed mold fabrication and size optimization of silver-coated carbon nanotubes

The development of 3D print technology provided an opportunity to achieve fast and accurate fabrication of wearable sensor arrays. In this paper, high-sensitivity flexible and stretchable silver-coated carbon nanotube (Ag@CNT) wearable strain sensor arrays are fabricated using 3D printing technology and composite nanomaterial synthesis. Ag@CNTs with uniform and compact particles were synthesized with different sizes of carbon nanotubes (CNTs) using a reduction method. Strain sensor arrays were fabricated accurately and efficiently with the aid of 3D printed molds. Sensors with different Ag@CNTs were then compared comprehensively, and it was found that the Ag@CNT (short) sensor, which had a gauge factor (GF) of 62.8 in the 0% to 14.44% stretch range and a GF of 831.3 in the 14.44% to 21.11% stretch range, can significantly enhance the detection of small movements. These wearable strain sensor arrays were utilized in the application of traditional Chinese medicine pulse diagnosis and gesture recognition.