Projects: Insect lenses and Spectroscopic Analysis

Examining the Spectral Signature of Insect Lenses (Visible Spectrum)

I wanted to examine specific wavelengths that are able to pass through the lens of insect eye.The plan was to choose eight Missouri insects : Honeybee, Red Paper wasp, Cicadas, Common Sand dragon, Green Mantis,Green Stripped Grasshopper,Reddish Brown Stag Beetle. I humanely collected (mostly found dead) each sample and dissected each specimen for the eye structure and preserved each sample in a non-alcoholic resin. Each sample was roughly 0.3-0.5 mm in size when preserved in the resin. I mostly choose this size to both test my ability of specifically cutting the lenses to a size and this size completely covers the viewing area at the desired magnification.

This post is mostly about the technical build and not about the study of the lenses although Ill post some of that data in the end for some insects tested.

Light source

The light source used was an array of white LEDs which had good spectral variance and could cover the wavelengths that I wanted to focus on.

Monitoring the wavelengths

So I decided to kinda cheat at this and use an off the shelf sensor for detecting and monitoring the intensities of the wavelengths other than using a broad spectrometer . Sparkfun produces a board called the AS726 Visible Spectrum breakout board. I purchased both the Visible and the NIR but for this I only used the Visible because thats mostly what the light source is focused on.

The Visible spectrum board has good wavelength variety, 450,500,550,570,600,650 nm. For my project this gives me enough information . Using a spectrometer would have opened up what wavelengths I could monitor but the breakout board takes away a lot of possible software issues and I like the idea of being in control of the code.

Microscope Attachment

The breakout board needed some form of case to properly attach to the microscope. So to try something new I decided to give Tinkercad a shot and I thought it came out great.

All of the prints were printed in Black PLA. In hope to stop any stray light

I designed a wire guide into the casing to length the life span of the project. The wiring leads to a male USB because the AS726 only needs four wires as it uses I2C communication. This leads to a female USB which is attached to a Arduino Mega as the image shows below. I can easily attach either of the breakout boards without having to rewire the Arduino.

If you hook up both the NIR and the Visible light sensors like above ^ this gives you 12 wavelengths to monitor and play around with . Hypothetically you could possibly use this type of setup to examine micro custom lens and filters. I have plans on attempting to build lenses that block specific wavelengths and hopefully that will be another post in the future.

Insect Lens Data

So below is a few data samples I got from the setup

Resin Sample