Abels Claudio, Qualtieri Antonio, Lober Toni, Mariotti Alessandro, Chambers Lily D, De Vittorio Massimo, Megill William M, Rizzi Francesco
Center for Biomolecular Nanotechnologies @UNILE, Istituto Italiano di Tecnologia, Arnesano (LE), I-73010, Italy.
Rhine-Waal University of Applied Sciences, Faculty of Technology and Bionics, Kleve, D-47533, Germany.
Beilstein J Nanotechnol. 2019 Jan 3;10:32-46. doi: 10.3762/bjnano.10.4. eCollection 2019.
Flow stimuli in the natural world are varied and contain a wide variety of directional information. Nature has developed morphological polarity and bidirectional arrangements for flow sensing to filter the incoming stimuli. Inspired by the neuromasts found in the lateral line of fish, we present a novel flow sensor design based on two curved cantilevers with bending orientation antiparallel to each other. Antiparallel cantilever pairs were designed, fabricated and compared to a single cantilever based hair sensor in terms of sensitivity to temperature changes and their response to changes in relative air flow direction. In bidirectional air flow, antiparallel cantilever pairs exhibit an axially symmetrical sensitivity between 40 μV/(m s) for the lower air flow velocity range (between ±10-20 m s) and 80 μV/(m s) for a higher air flow velocity range (between ±20-32 m s). The antiparallel cantilever design improves directional sensitivity and provides a sinusoidal response to flow angle. In forward flow, the single sensor reaches its saturation limitation, flattening at 67% of the ideal sinusoidal curve which is earlier than the antiparallel cantilevers at 75%. The antiparallel artificial hair sensor better compensates for temperature changes than the single sensor. This work demonstrated the successive improvement of the bidirectional sensitivity, that is, improved temperature compensation, decreased noise generation and symmetrical response behaviour. In the antiparallel configuration, one of the two cantilevers always extends out into the free stream flow, remaining sensitive to directional flow and preserving a sensitivity to further flow stimuli.
自然界中的流动刺激多种多样，包含各种各样的方向信息。大自然已经发展出形态极性和双向排列用于流动感知，以过滤传入的刺激。受鱼类侧线中神经丘的启发，我们提出了一种基于两个弯曲悬臂的新型流量传感器设计，这两个悬臂的弯曲方向彼此反平行。设计、制造了反平行悬臂对，并将其与基于单悬臂的毛发传感器在对温度变化的敏感度以及对相对气流方向变化的响应方面进行了比较。在双向气流中，反平行悬臂对在较低气流速度范围（±10 - 20 m/s之间）下表现出40 μV/(m·s)的轴对称灵敏度，在较高气流速度范围（±20 - 32 m/s之间）下表现出80 μV/(m·s)的轴对称灵敏度。反平行悬臂设计提高了方向灵敏度，并对流动角度提供正弦响应。在正向流动中，单个传感器达到其饱和极限，在理想正弦曲线的67%处趋于平坦，这比反平行悬臂在75%处更早。反平行人造毛发传感器比单个传感器能更好地补偿温度变化。这项工作展示了双向灵敏度的持续改进，即改进的温度补偿、减少的噪声产生和对称的响应行为。在反平行配置中，两个悬臂中的一个总是延伸到自由气流中，对方向流动保持敏感，并对进一步的流动刺激保持灵敏度。
