- Whisker Sensor

ACTIVE SENSING

    Rodents, specially rats, can recognize distance and shape of an object and also pattern of the textures by using their whiskers. Mechanoreceptors surrounding the root of whisker in their follicle measure deflection of the whisker.


Active sensing of rat's whikser

MAKING WHISKER SENSOR

    Rats can move their whisker back and forth freely. This ability, called active whisking or active sensing, is one of characteristics of rat‘s behaviour. Many researches based on the mechanism have been progressed. we designed biomimetic whiskers modeling after a structure of follicle using the microphone.


Scheme of the Microphone Whisker sensor


Performance of the Microphone Whiskersensor

PERFORMANCE

    The microphone sensor measures a mechanical vibration. Attaching an artificial whisker beam to the microphone membrane, we can detect a vibration of whisker and this can show the deflection amount of whisker indirectly. We test several kinds of animal whiskers to figure out that the sensor can recognize the each animal's characteristics.


(a) Dog (b) Cat (c) Pig (d) Tiger (e) Goat (f) Opic fiber(0.2pi) (g) Opic fier(0.5pi)


(a) Dog (b) Cat (c) Pig (d) Tiger (e) Goat (f) Opic fiber(0.2pi) (g) Opic fier(0.5pi)

    The Microphone WhiskerSensor also can detect the distance from objects measuring the angle at the root of the beam. We have done distance detecting experiment.

Distance - checking motion


Distance - voltage value diagram


COMPARE WITH OTHER SENSORS

    In order to identify the microphone sensor's performance, a comparative study could be good exmaple.  To compare whisker sensor's performance with other sensors, we made a series of sensors including a whisker sensor, magnetic sensor and piezo-electric sensor.


magnetic(top) piezo(middle) microphone(bottom)


magnetic sensor


piezo electric sensor


microphone sensor

SHAPE RECOGNITION

    Basically, a shape is a set of distances from one point. Since the whisker sensor can measure distances, the microphone sensor can recognize a shape of an object.