# Title Team Members TA Documents Sponsor
27 Capacitance Sensors for Mason Bee Activity Measurement
Jyotsna Joshi
Keerat Singh
Piyush Sud
Amr Ghoname design_document2.pdf
Team Members:
- Jyotsna Joshi (jyotsna3)
- Keerat Singh (keerats2)
- Piyush Sud (psud2)

# Problem

The well-known loss of pollinators around the world has been a concern for ecologists, agriculturalists, farmers, and everyday citizens for several years now. While the exact reason for the infamous Colony Collapse Disorder affecting honeybees is unknown, there is work being done on boosting their populations so that honeybees can be the thriving pollinators they were once. But what if we are focusing too squarely on the honey bees? What if there is a more effective way to pollinate crops and native plants with a bee population that is native to North America? That would be the mason bees, megachilidae osmia. Mason bees, solitary bees that don’t live in hives, don’t make honey, and usually don’t sting, are a species of bee that can pollinate an area almost 100 times more efficiently than the western honeybee. They are a good species for even amateur apiarists to keep near their homes to boost local native bee populations and participate in solving global ecological issues.

There are some key hurdles to keeping mason bees. Mason bees live in “tunnels”; in nature, this means they live in dark crevices found in trees, rocks, or in the ground, but kept bees live in tunnel homes. Please refer to Figures 1.1 and 1.2 to see examples of these tunnel nests.
## Types of Tunnel Nests
![Figure 1.1: Bamboo tunnels in containers](

Figure 1.1: Bamboo tunnels in containers

![Figure 1.2: Wood block with holes drilled in to make tunnels](

Figure 1.2: Wood block with holes drilled in to make tunnels

Female bees will populate these tunnels with eggs for next year, and seal tunnels when they are done laying their eggs. Beekeepers must clean these tunnels, especially at the end of every season, and harvest the bee cocoons for the next year. However, it can be challenging to know when to clean a tunnel, especially if one is unable to tell if the tunnel is occupied by an alive adult bee. This difficulty arises from the fact that these tunnels are long and dark, and so bee activity deep inside the tunnels is hard to gauge.

# Solution
We propose a solution to the specific issue of not being able to tell whether a bee tunnel of a mason bee house is populated by a live, adult bee. We intend to do this by constructing a mason bee house with 6 to 8 tunnels with capacitance sensors along each tunnel to detect a) how full each tunnel is and b) whether bee activity is still sensed at the mouth of the tunnel.

We plan to use a change in capacitance to understand when bees are in their tunnels; by placing capacitance sensors along the tube at intervals [Figure 2 shows how tunnels are sectioned off as they are filled with eggs; we will approximately place our sensors along where these walls may be constructed], we hope to measure the change in dielectric constant between capacitor plates or rings as bees or other organisms pass by the sensors.

We plan to use the asynchronous voltage pulses generated by bees moving by different sensor points to infer information about the organism’s size and velocity.
When it is determined that a tunnel is no longer actively occupied by an adult bee, the beekeeper can remove the unoccupied tunnel and store it away indoors to keep the pupae inside the tunnels safe from fungal infections and parasites until it is time to harvest their cocoons.
For testing and demonstration, we will be using steel or epoxy resin balls to simulate bee entrance and exit behaviours.

![Figure 2: Eggs in their pollen ball walled off by the female mason bee who laid them](

Figure 2: Eggs in their pollen ball walled off by the female mason bee who laid them

# Solution Components

## Housing
- We plan to build a wooden structure and drill holes in the main body of wood to create tunnels. See Figure 1.2 for tunnel reference.
- The tunnels will have the capacitance sensors embedded in them along the length of the tube.
- Paper and/or cardboard sleeves will line the inside of the tunnel, so that they can be pulled out from the nest at the end of the season for cocoon harvesting. This will make the larger wooden structure easier to clean and reusable.
- The wooden structure will have an exterior compartment to hold the microcontroller, microSD card, power supply access and other required circuitry. This will give beekeepers easy access for maintenance and also protect against tampering by bees.

## Capacitance Sensors Setup:
- We will either have pairs of capacitor rings or we will have capacitor plates on either side of the tunnel; the final design will be selected after discussing with the machine shop to see which will be easier to integrate into the mason bee house. These capacitors will be used as points of measure along the bee’s path, and will be set up using an “AC bridge and phase sensitive detection”. This will lead “asynchronous voltage pulses” to be generated as the bee walks by these sensors, and so we can infer behaviour by observing magnitude and time delay between pulses.
- Capacitor sensors will be placed in every tunnel in the nest. Collected sensor data will go to a microcontroller for processing so we can identify which tunnels are occupied, how much of a tunnel is filled with eggs, and whether the organism moving inside the tunnel is a mason bee or a parasite.
- This set-up is based on research conducted at the University of Prince Edwards Island by Jennifer M Campbell et al, and has been described in the paper “Capacitance-based sensor for monitoring bees passing through a tunnel”. See sources section below for more information.

## Data Collection
- We will start off by writing data collected to a microSD card, so that the data can be easily retrieved from the nest and be viewed on a PC.

## Power
- To make installation easy for beekeepers, we want to use a wall outlet power supply that will supply 5V via a Micro USB connector [like on a Raspberry Pi].

# Criterion for Success
##Main Goals
- System differentiates between unoccupied tunnels [with or without eggs] and tunnels with active adult bees. Bees simulated with steel or resin balls rolled into the tunnels.
- System understands how full each tunnel is with eggs. Eggs will be simulated with the same material as bees.
- System detects activity at the mouth of the tunnel to be able to detect exit/entry behaviours.
- System accurately collects and time-stamps data; data is processed to some level to give insights to beekeepers on bee activity.

## Stretch Goals
- Additional sensors are added to the nesting block to frame bee activity in context of environmental data (temperature, humidity).
- Nest tunnels can be sealed off if left unsealed [i.e, in case that mother bee dies] to prevent spread of fungal infections and parasites.
- Data is displayed on an accompanying screen or mason bee house is paired to an app on beekeeper’s phone.
- Mason house design is expanded to include an “attic” where cocoons can be readied to hatch in the spring. Beekeepers can be notified of the ideal time to place cocoons in the attic if it is integrated with temperature and humidity sensors that measure those values inside and immediately outside the attic.

# Sources
Bee Built. (2017). How to Keep Solitary Bees. Youtube. Retrieved January 31, 2022, from

Bee Built. (2017). Introduction to Solitary Bees. Retrieved January 31, 2022, from

Campbell, J. M., Dahn, D. C., & Ryan, D. A. (2005). Capacitance-based sensor for monitoring bees passing through a tunnel.
Measurement Science and Technology, 16(12), 2503–2510.

Mader, E., Shepard, M., Vaughan, M., & Guisse, J. (2018, May). Tunnel Nests for Native Bees. Retrieved January 25, 2022, from

Paul Wheaton. (2014). Mason Bee Micro Documentary. Youtube. Retrieved January 31, 2022, from

Growing Degree Day Monitor

Anthony De Roo, John Habegger, Jay Zhaoyu Yao

Featured Project

The purpose is to create an inexpensive growing degree day monitor that records temperature and computes growing degree days for a specific farming field during a growing season. This monitor will be placed near a farm field where it will monitor temperature conditions during the growing season. It will record both the ambient air and soil temperatures over the course of day. These temperatures will then be used to calculate the growing degree days. The cumulative number of degree days will then be displayed on either a seven-segment display or this can be downloaded to a computer. This monitor will be powered through a combination of both solar and battery power.