Constructing microstructures to improve the sensitivity of flexible pressure sensors is an effective approach. However, the preparation of microstructures usually involves inverted molds or subtractive manufacturing methods, which are difficult in large-scale (e.g., in screen printing) preparation. To solve this problem, we introduced thermally expandable microspheres for screen printing to fabricate flexible sensors. Thermally expandable microspheres can be constructed into microstructures by simple heating after printing, which simplifies the microstructure fabrication step. In addition, the added microspheres can also be used as ionic liquid reservoir materials to further increase the capacitance change and improve the sensitivity. The prepared sensors exhibited superior performance, including ultrahigh sensitivity (S_max = 49999.5 kPa^–1) and wide detection range (0–350 kPa). Even after 30,000 cycles at a high pressure of 300 kPa and a low pressure of 30 kPa, the sensor showed minimal signal degradation, demonstrating long-term cycling stability. In order to verify the practical potential of the sensors, we performed human radial artery beat detection experiments using these sensors. The variations in the intensity of the 3D radial artery pulse wave can be observed very clearly, which is important for human health monitoring. The above demonstrates that our strategy can provide an effective approach for the large-scale preparation of high-performance flexible pressure sensors.

中文翻译：

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用于脉冲监测的具有热膨胀微球的丝网印刷离子压力传感器


构建微结构来提高柔性压力传感器的灵敏度是一种有效的方法。然而，微结构的制备通常涉及倒置模具或减材制造方法，这在大规模（例如丝网印刷）制备中是困难的。为了解决这个问题，我们引入了用于丝网印刷的热膨胀微球来制造柔性传感器。热膨胀微球在打印后通过简单的加热即可构建成微结构，从而简化了微结构的制造步骤。此外，添加的微球还可以作为离子液体储库材料，进一步增大电容变化，提高灵敏度。所制备的传感器表现出优越的性能，包括超高灵敏度（S _max = 49999.5 kPa ^–1 ）和宽检测范围（0–350 kPa）。即使在 300 kPa 高压和 30 kPa 低压下进行 30,000 次循环后，传感器仍显示出最小的信号衰减，证明了长期循环稳定性。为了验证传感器的实际潜力，我们使用这些传感器进行了人体桡动脉搏动检测实验。可以非常清晰地观察到3D桡动脉脉搏波强度的变化，这对于人体健康监测很重要。以上表明，我们的策略可以为大规模制备高性能柔性压力传感器提供有效的方法。