基于双层平面螺旋电感的无线柔性压力传感器结构设计

Structural Design of Wireless Flexible Pressure Sensor Based on Double-Layer Planar Spiral Inductor

新型柔性传感器在电子皮肤、智能纺织、柔性机器人等领域得到了广泛的研究。目前多数传感器需要连接刚性的采集电路,这限制了设备柔软性、舒适性和轻盈度的提升。提出了一种基于双层平面螺旋电感的柔性无线无源压力传感器。该传感包含三层柔性层:双层平面螺旋电感(天线层)、高磁导率铁氧体膜和弹性织物层。其中,双层平面螺旋电感层包括两个旋转方向相反的平面线圈,形成具有大电感量、大电容量的LC谐振器。外界压力载荷改变传感器的谐振频率,进而被外界接收线圈无线检测。通过研究四种双层螺旋电感天线层的结构设计,传感器的灵敏度最大可达到0.11 MHz/k Pa,检测距离达到18 mm。这种基于双层平面螺旋电感的柔性无线无源压力传感器打破了有线电气连接的限制,可在下一代医疗系统、智能机器人等领域中发挥巨大的应用潜能。

State-of-the-art flexible sensors have been widely studied in electronic skin,intelligent textile,flexible robot,etc.Most sensors need to be connected to rigid acquisition circuits,which limits the flexibility,comfort and lightness of the devices.A flexible wireless passive pressure sensor based on double-layer planar spiral inductors is reported.The sensor composes of three flexible layers,i.e.,double-layer planar spiral inductor(antenna layer),ferrite film with high permeability and elastic fabric layer.Specially,the double-layer planar spiral inductor layer consists of two planar coils with opposite rotation directions,forming an inductance-capacitance(LC)resonator with large inductance and capacitance.The pressure-dependent resonant frequency of the sensor is wirelessly detected through an electromagnetically coupled charging coil/receiver.By investigating the structural design of four kinds of double-layer spiral inductor antennas,the sensor achieves the sensitivity of as high as 0.11 MHz/kPa and the detection distance up to 18 mm.The wireless passive pressure sensor based on double-layer planar spiral inductor architecture breaks the limitation of wired electrical connections,showing a great application potential in the fields such as the next-generation of healthcare systems and intelligent robotics.