Solar Scare Mosquito by gallactronics

Every year, over a million people are killed by malaria. The only solution to this problem is to destroy mosquito breeding grounds and curb the problem at source. As mosquitoes breed in stagnant water, I concluded that surface aeration would be one of the best means of eliminating breeding grounds.

So I built a device that generates air bubbles at regular intervals and effectively produces ripples up to a radius of 2 meters (sufficient for most urban water bodies). The device automatically switches on when it comes in contact with water an alarm alerts if the water body dries up or someone tries to remove the device from water. At less than $10, the device is cost effective and being solar powered, it is energy independent and maintenance-free.

Here is the project description on Youtube: Solar Scare Mosquito

Note: You will have to see this video to fully understand and appreciate the project.

For further details, visit: http://www.gallactronics.com/

Step 1: Hypothesis

More than half the world’s population is vulnerable to vector-borne diseases. These diseases, namely malaria, largely affect children and poor people and there is no promising solution to eradicate it.

Question: So how can we control malaria using technology?

As mosquitoes transmit malaria and water stagnation is the primary cause of mosquito-breeding, by preventing water stagnation, it should be possible to curb malaria.

Hypothesis: By devising a surface aeration system for small water bodies, it should be possible to control mosquito breeding. 

Step 2: Don’t stagnate… Research!

The primary reason why mosquito breeding cannot be easily controlled is that all breeding grounds need to be either regularly emptied or regularly treated with insecticides. Regularly emptying surrounding objects is tedious and often not practical. And employing people to regularly treat water bodies with larvicides and fogging is expensive. Therefore potential breeding grounds are not maintained and stagnant water in common elements of a cityscape like birdbaths, rain barrels, water reservoirs, ponds, swamps and sewage lines become vulnerable to mosquito breeding.

On evaluating the ideal conditions for mosquito breeding, I concluded that surface aeration would be the ideal solution to control this breeding because of the following reasons:

  1. Surface turbulence will prevent mosquitoes from laying eggs on water as mosquitoes can lay eggs only if the water is completely still.
  2. If they do succeed in laying eggs, the eggs may drown or get damaged with the turbulence.
  3. If the eggs hatch, the larvae will not be able to remain on the turbulent surface and get exhausted in the process of diving down and resurfacing.
  4. As the larvae will not be able to remain on the surface and breathe, they will suffocate and ultimately die.
  5. Moreover, surface aeration will reduce anaerobic bacterial development and deplete larval nutrition from the microlayer.

Having concluded that theoretically surface aeration is the key to controlling mosquito breeding, I went on to verify my hypothesis through experiment.

Step 3: Building the Device

Picture of Building the Device
Solar Scare Mosquito Design.jpg

The device comprises of the following parts:

Bubble aeration

I chose bubble aeration to create surface turbulence as it requires less power and maintenance than other methods of aeration, such as the use of an impeller or a fountain. For this prototype, I used a portable aquarium pump as a bubble generator.

Solar Power

As the aerator needs to run perpetually, it is not practical to make it battery-powered as the battery would have to be replaced often. So I made the device solar powered. Here, I’ve used a 6v 3w panel.

Night-activation

As most mosquitoes lay eggs between dusk and dawn, the device would be most effective at night. And so with the help of an LDR, which is a light intensity sensor, the device runs only when it’s dark. During the day, the solar panel charges Li-ion batteries and these batteries run the aerator at night.

Timer

A 555 timer circuit switches the pump on and off at intervals of 10 minutes to increase the life of the pump.

Automatic Start

In the case of rainwater, roadwork and construction sites, no arrangements are made to treat such temporary water bodies that are potential breeding grounds.

So to deal with this problem, the aeration device automatically starts when it comes in contact with water so that it can be installed in a catchment area and when water gets collected, it starts running immediately and leaves no room for mosquito breeding.

Alarm

The device also includes an inbuilt alarm to alert if the water body dries up or someone tries to remove the device from water.

Step 4: Get your hands dirty

Picture of Get your hands dirty
Solar aerator Circuit diagram.png

This is the best part of the project…building the circuit! It takes no time to build this circuit which could potentially save you from those nasty mosquito bites. So get tinkering!

Components:

  1. 6V 450mA Solar Cell
  2. Portable aquarium aerator
  3. 2 x Lithium Ion Rechargeable Batteries (laptop batteries – 18650A)
  4. Piezo Buzzer
  5. Perfboard
  6. 555 Timer IC
  7. 3 x 2N3904 NPN Transistors
  8. BD135 NPN Transistor
  9. Heat sink
  10. Capacitors – 470 uF, 0.1 uF
  11. Resistors – 220 ohms, 470 ohms, 2 x 10 k, 100k, 1M.
  12. Indicator LED
  13. Toggle switch
  14. Jumpers

Electronic Parts:

  1. 6V 450mA Solar Cell
  2. Portable aquarium aerator
  3. 2 x AA Rechargeable Batteries (I used 2 AA alkaline batteries as I did not have rechargeable ones)
  4. Piezo Buzzer
  5. Perfboard
  6. 555 Timer
  7. 3 x 2N3904 NPN Transistors
  8. BD135 NPN Transistor
  9. Heat sink
  10. Capacitors – 470 uF, 0.1 uF
  11. Resistors – 220 ohms, 470 ohms, 2 x 10 k, 100k, 1M.
  12. Indicator LED
  13. Toggle switch
  14. Jumpers

Other materials:

  1. Casing
  2. 3 x 2″ Stainless Steel bolts (that will serve as water probes)
  3. PVC pipe and fittings
  4. Miscellaneous tools

Step 5: Observation, Experimentation and Results

Picture of Observation, Experimentation and Results

To test the device, I installed it in a small pond where rainwater had recently collected.

I waited until mosquito larvae began appearing in the pool to ensure that the pool was suitable for mosquito breeding. About three days after the larvae were born, I installed the aerator in the pond and observed the larval population in the pond. The results of the experiment are tabulated in the image above (I did not provide photos of the experiment as the larval population in the pond was not visible in the photos).

The experiment shows that while the aerator was not sufficiently powerful to suffocate and kill the full-grown larvae, within two hours it wiped out the majority of the young larval population and ensured a mosquito-free water body thereafter.

Step 6: A Mosquito-free Tomorrow

Picture of A Mosquito-free Tomorrow

My observations have shown that, by preventing water stagnation by means of aeration, it is possible to control mosquito breeding and thereby control the proliferation of malaria.

The aeration device that I have built costs less than $ 10. Considering that every year, the global medical expenditure on malaria control amounts to over US$ 6 billion, ubiquitously installing this device in villages and cities would cost only a fraction of that amount.
I hope that, one day this cost effective and sustainable device will save the world valuable money and priceless lives.

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