Development Milestones

Name	Types of Plastic	Form Factor	Material	Interpretation	Enviroment	Material cost	Certainty	database type
Proof of concept	1	computer connected	3D print	Computer	In the Dark	1000	80% sure	local database
Minimum Viable Product	5	computer connected	3D print	Computer	In the Dark	1000	80% sure	local database
Cool Plastic Scanner	5	Handheld	3D print	Computer	Open	800	80% sure	Computer database
Great Plastic Scanner	5	Handheld	recycled	On device	Open	300	90% sure	online own database
Ultimate Plastic Scanner	5+	Handheld	recycled	On device	Open	100	95% sure	Big open database

Proof of concept

Status: 🧑‍💻In progress

Objective 1: Physics characteristics of components.

Describe and measure the components used to make sure that then can execute the desired task.

Tasks:

• Charicterise LED driver
  • Is it possible to drive the leds with constant signal.
  • How long can the LED be on
  • Is there a startup time
  • At what point do the LEDs give a constant amounth of light.
• Make PCB to test LED and InGaAs sensor
  • Make a PCB that can hold up to 8 leds in a circulair pattern, use 2.54mm pins to power them. add a pad for an InGaAs sensor in the middle.
• Characterise LED
  • Solder one of the leds on the board, power it according to the specs of the datasheet, measure its spectrum with a spectrometer. Compare this to the datasheet.
  • How constant are the leds over time?
  • What is the light output as a function over time if it is one?
  • How quickly do the leds degrade?
• Charicterise InGaAs sensor
  • Solder on a separate board an InGaAs sensor, turn on different leds and measure if you get the expected sensitivity.
  • Does it make sense to measure as an interger
  • How consistant are repeated measurements
  • What is the background noise
• Charicterise Analog frontend
• Charicterise ADC

Required materials:

• Ossiloscope
• Powersupply
• Power output meter
• Industrial spectrometer

Estimated time:
Not taking into account lead time of pcb, and access to required material, the testing itself is quite straight forward. Expected around two weeks of work by a single person.

Estimated outcome:
A report that concludes if the leds and InGaAs sensor are able to do discrete spectroscopy.

Objective 2: Ideal setup of the sensor cavity

Once we know that the characteristics of the components we can make an theoretically ideal sensor cavity that provides the maximum amounth of information for the sensor.

Unknowns:

Is it possible to fully develop this based on only theory? or do we need tests or prototypes? Tasks:

• Determine which wavelengths of LEDs are used
• Determine height between LED, sample and sensor
• Determine height between devider wall between LED and sensor
• Determine coating on walls

Required material

• Reference sample
• 3D printer

Estimated time

Estimated outcome
Suggested design of sensor cavity that has the highest change of succesful readings. which includes a design of a pcb with the layout of the componentns and 3D designs that can be printed with an FDM printer

Objective 3: Create Proof of concept

Once we know how the sensor cavity needs to look like we can develop the rest of the proof of concept.

Unknowns:
Tasks:

• Determine how the InGaAs sensor needs to be measured
  • use of an opamp
  • use of a high precision ADC
  • Requirements for reference voltage
• Design a setup that incorporates LEDs, LED driver, InGaAs sensor, required amplification, microcontroller, and a way for input and output.
• Design hardware components required to get the optimal sensor cavity defined in Objective 2.
• Compare the built proof of concept with the expected values. Required material
  Estimated time
  Estimated outcome
  a setup to measure various plastics, this can include off the shelve modules for the ADC or LED driver.

Objective 4: Comparisment of "pure" plastics between proof of concept and industrial spectroscope.

The goal of the Objective is to get an idea how this discrete setup compares to an industrial setup, and to see if it is possible to get comprable spectra.

Tasks:

• Find plastics with little to no additives
  • go to plastic product manufacturers
  • go to polymer manufacturers
• setup experiment to capture spectra from these samples
  • capture spectra from samples with industrial spectroscope
• Compare spectra from these samples to our measurements
  • Capture data with our setup
• Compare to known spectra
• Calculate/optimize distance between sample and sensor

Required material

• Pure plastic granulate
• Industrial spectroscope

Estimated time
Estimated outcome
A report that compares the samples measured with industrial spectrometer and our setup. and an improved sensor cavity

Minimum Viable Product

Status: 🔜 Not started yet.
First need to have proof of concept finished.

Cool Plastic Scanner

Status: 🔜 Not started yet.

Great Plastic Scanner

Status: 🔜 Not started yet.