Development of extremely large area light-emitting-diode-embedded fabric and investigation of its mechanical properties

We have developed a meter-scale extremely large area LED-embedded soft fabric for three-dimensional complicated shapes such as furniture, tents, and ceilings by transforming the shape of a lighting fabric. The developed meter-scale large-area LED-embedded fabric was assembled by a process in which LED-mounted 5 × 20 mm pieces of printed circuit board (PCB) were first soldered to a 2-cm-wide ribbon with copper power lines, then the resultant ribbons were woven as wefts by using a 1.2-m-wide automatic weaving machine. Fabrication with automatic weaving can produce a large (1.2 m × 1.2 m), lightweight (0.224 kg/m²) LED lighting fabric. The mechanical flexural rigidity of the LED fabric was investigated by comparing it with conventional flexible PCBs. The resultant bending stiffness of the LED fabric was 7.92 × 10⁻⁵ Nm²/m, which is smaller than that of PCBs, allowing the fabric to be bent easily. The hysteresis width of the bending stiffness of the LED fabric was 8.03 × 10⁻³ Nm/m, which is larger than that of PCBs, meaning that the fabric can keep its shape under bending. Finally, we demonstrated the illumination of rooms and gardens using the LED-implemented fabric by installing it on ceilings and tents with three-dimensional complicated curved shapes.