Affordable Bimodal Optical Sensors to Spread the Use of Automated Insect Monitoring

Figure 1

(a) Sensor. An illustration of the bimodal sensor concept. The light of the infrared LED (bottom) passes through the Fresnel lens and is collimated. The insect’s wingbeat casts a shadow to the opposite receiving Fresnel lens (top). The collimated light is also partially side scattered at 90° and directed to the passive Fresnel lens that records the reflected light (a). (b) A CAD design of the prototype sensor. A cone-shaped, dark plastic fixes the LED and photodiodes to their correct focal point.

(a)

(b)