Application Cases

Experiment Title: Study on Tactile-Controlled Electroluminescent Yarn and Its Pressure Response Performance

Research Direction: This experiment focuses on the visual interaction applications of pressure-sensitive electroluminescent yarn. A flexible electroluminescent yarn is prepared using a twisting process and combined with pressure-sensitive fabric based on the piezoresistive effect to construct a touch-sensitive electroluminescent yarn. The pressure-sensitive fabric serves as the pressure-sensing end, exhibiting high sensitivity (approximately 0.4095 kPa⁻¹ in the low-pressure range), fast response time (<50 ms), and excellent cyclic durability (>8000 cycles), enabling effective perception, recording, and differentiation of human motion pressure for dynamic monitoring and touch-control functionality. The flexible electroluminescent yarn serves as the light-emitting response end, achieving a brightness of 80.93 ± 4.00 cd/m², which meets the illumination requirements for nighttime reading. The construction of touch-sensitive flexible electroluminescent yarn enables instant light emission in response to pressure stimuli, providing a practical solution for efficient visual interaction in fields such as smart wearables, sports training, and healthcare.

Experimental Objective: This experiment aims to prepare flexible electroluminescent yarn using a twisting process and combine it with pressure-sensitive fabric to achieve light-emitting responses to pressure stimuli.

Test Equipment: ATA-7025 high-voltage amplifier, function signal generator, imaging luminance meter, spectral luminance meter, electron microscope, infrared thermal imager, etc.

Figure 1: Schematic and Physical Image of Touch-Sensitive Electroluminescent Yarn

Experimental Process:
Touch-sensitive electroluminescent yarn is prepared, and the sensing performance of the pressure-sensitive fabric is tested. The flexible electroluminescent yarn is then driven using a function signal generator (output frequency: 10–10,000 Hz, output voltage: 2 V) and a high-voltage amplifier (amplification factor: 0–1000). The brightness of the flexible electroluminescent yarn under different electric field conditions is characterized using an imaging luminance meter (integration mode: fixed mode, fixed time: 10 ms), followed by other tests and characterizations.

Experimental Results:

Figure 2: Sensing Performance of Pressure-Sensitive Fabric (a) Sensitivity, (b) Response Time, (c) Resistance Changes Under Different Pressures, (d) Stress-Strain Curve, (e) Cyclic Durability

The sensitivity of a single monitoring unit of the pressure-sensitive fabric is tested, and the results are shown in Figure 2. It can be observed that the pressure-sensitive fabric exhibits different sensitivity characteristics across various pressure ranges. In the low-pressure range (0–3 kPa), the pressure-sensitive fabric shows a sensitivity of 0.4095 kPa⁻¹ with good linearity. As the pressure increases, the linearity deteriorates. When the pressure is in the higher range (>70 kPa), the sensitivity decreases to 0.0107 kPa⁻¹. This is due to the working mechanism of piezoresistive flexible sensors.

Figure 2c illustrates the resistance changes of the pressure-sensitive fabric under different pressures. It is observed that after applying a certain pressure to stabilize the initial resistance of the pressure-sensitive fabric, placing a 2g weight reduces the resistance of the monitoring unit from 22,280 Ω to 21,478 Ω, resulting in a resistance change rate exceeding 3%. When 10g, 20g, 50g, 100g, and 200g weights are sequentially placed, the resistance change rates are 32%, 41%, 65%, 70%, and 76%, respectively. The stable pressure monitoring range is approximately 0.544 kPa to 54.444 kPa. This is primarily attributed to the excellent mechanical properties of the 1+1 rib conductive fabric, which enables significant deformation under small external forces, leading to rapid changes in resistance and excellent responsiveness.

High-Voltage Amplifier Recommendation: ATA-7025

Figure: ATA-7025 High-Voltage Amplifier Specifications