This Solar-Powered Bottle Cleans Water!

Hello, in this Instructable you will learn how to build a water bottle that sterilizes the water present in it, using ultraviolet light rays. It is estimated that 1.3 Billion plastic water bottles are used every single day across the globe. This translates to about 1 million plastic water bottles being used per minute around the world. Around 250,000 water bottles have been used since you started reading this Instructable.

The widespread use of plastic bottles poses significant health risks, especially since many of these bottles are made from low-quality plastics. With the discovery of microplastics, the situation has become even more alarming. Microplastics are tiny plastic particles that can enter the human body through drinking water, causing various health issues.

Our solution is both simple and highly effective. By tackling the problem at the domestic level, we aim to make our solution widely accessible to the end-user. This approach ensures that real-world implementation is practical and rapid. Read on to discover our innovative solution and learn how you can create one for yourself.

This project was created by Riddhi Gupta and Aarav Garg, students at Purdue University.

1.1 Public Health Threats from Contaminated Drinking Water

Contaminated drinking water poses a significant public health threat globally, with pollutants ranging from microorganisms to industrial chemicals. Microbial contamination, often from inadequate sanitation and improper sewage disposal, can lead to diseases such as diarrhea, dysentery, and hepatitis. According to the World Health Organization, poor water quality is linked to 80% of diseases in developing countries, contributing to high child mortality rates and widespread illness​​.

1.2 Alarming Rise of Microplastic Contamination

The problem of microplastic contamination in drinking water has become increasingly alarming. Studies have found that a significant percentage of bottled water contains microplastics, with research from Orb Media revealing that 93% of sampled bottled water brands showed microplastic contamination​. These microplastics originate from the breakdown of plastic bottles and caps during production, transportation, and storage. Once ingested, microplastics can pose unknown health risks, as they have the potential to accumulate in the human body and cause various health issues, including disruptions to the endocrine system and inflammatory responses.

1.3 Strategies for Addressing Water Contamination

Addressing water contamination requires a multifaceted approach, including improved water treatment infrastructure, stricter regulations on pollutants, and international cooperation. Efforts to enhance water quality must focus on both immediate solutions, like providing clean drinking water, and long-term strategies to reduce pollution at its source. Sustainable practices in agriculture and industry, along with advancements in water purification technology, are crucial.

The above-mentioned problems are indeed, very alarming, and call for an immediate solution, not only on an organizational level but also on an individual level.

2.1 Mechanism of UV Water Purification

Ultraviolet (UV) light purifies water by emitting germicidal wavelengths that disrupt the DNA of microorganisms, rendering them unable to reproduce and causing infections. Water passes through a chamber containing a UV lamp, typically emitting light at 254 nm, which penetrates the cells of bacteria, viruses, and protozoa, effectively inactivating them. This method does not remove the organisms but deactivates their ability to cause disease, making the water microbiologically safe for consumption​.

2.2 Advantages of UV Water Purification

The advantages of UV water purification are significant. It is highly effective against a wide range of pathogens, including those resistant to chemical disinfectants like chlorine. UV treatment does not produce harmful by-products, nor does it alter the taste or odor of the water, making it a safe and appealing option. Additionally, UV systems are cost-effective, easy to maintain, and capable of treating water almost instantaneously. They are environmentally friendly, requiring no chemicals and producing no disinfection by-products, while their low energy consumption enhances their sustainability.

3.1 Solar-Powered UV Sterilization System

Our solar-powered UV sterilization water bottle is engineered to harness solar energy efficiently to purify water. The bottle features a 6V, 80mA solar panel on its top, capable of generating 480mW of power. This energy is utilized to power two UV LEDs situated at the bottom of the bottle's cap, each contributing to the sterilization process. This setup ensures that the bottle remains portable and self-sufficient, providing a practical solution for individuals in areas without reliable access to electricity.

3.2 Meeting Disinfection Standards

The UV sterilization system is designed to meet the demanding standards for effective disinfection. Specifically, the system targets a minimum UV intensity of 16mW/cm² to ensure the water is adequately purified. The water level's interior surface area is approximately 43 cm², which ideally requires a total power output of 688mW to achieve this intensity. However, the actual power delivered by our UV LEDs is approximately 480mW, translating to an intensity of about 11.16mW/cm² across the sterilization area.

3.3 Efficiency and Performance

The achieved intensity reflects an efficiency of around 70%, based on the actual output compared to the ideal requirement. While this is below the stringent standard of 16mW/cm², it still provides significant disinfection capabilities. This efficiency is derived from the practical performance of the system, accounting for real-world variables such as energy conversion losses and the inherent characteristics of the UV LEDs. Thus, our design ensures that the bottle delivers substantial microbial reduction, making drinking water safer by utilizing sustainable solar power effectively.

These are the components, tools, and software you will require for this project:

4.1 Components Required

• Circular Solar Panel
• LED UV Light 390-395nm x2
• Connecting Wires

4.2 Tools (Optional)

• Soldering Iron
• Wire Cutter and Stripper
• Tweezers
• Sand Paper
• Anet ET 4 Pro 3D Printer
• White 3D Printer Filament

4.3 Software

• Autodesk Fusion (or) any other 3D CAD software
• Autodesk Eagle (or) any other schematic and PCB CAD software

We always prefer www.iamrapid.com for all of our 3D printing needs.

Gather all the required material and move on further to the next step!

Due to its convenience, we opted to utilize the Z-X plane in our fusion design for creating a standing water bottle. However, you can select any plane that suits your preferences and project requirements.

Also, we changed the color of the bottle using the 'Appearance' feature but it is completely optional!

5.1 Creating the Sketch of the Bottle

To start, sketch the base figure of the bottle, which will determine its overall shape and dimensions. Refer to the image provided for the specific appearance of the figure. Here are the detailed steps to create the sketch:

1. Draw a vertical line in the center of the plane, representing the axis of rotation, measuring 180 mm in height.
2. Draw a horizontal line from the base of this line, measuring 40 mm.
3. Draw a vertical line parallel to the inner axis line and at the other end of the baseline with a height of 160 mm.
4. From the top of the inner axis line, draw a horizontal line measuring 30 mm.
5. From the top of the outer line, draw a horizontal line measuring 10 mm.
6. Connect the endpoints of the two horizontal lines with a vertical line that should measure 20 mm.

5.2 Creating the 3D Model of the Bottle

With the sketch completed, you can now proceed to create the 3D model of the bottle using the 'Revolve' feature:

1. Use the Revolve tool to revolve the sketch around the inner axis line, forming the 3D shape of the bottle.
2. Select the edge of the base of the bottle and apply a fillet with a radius of 4 mm. This will smooth out the edge for a better finish.
3. Select the top of the smaller circle at the neck of the bottle and use the 'Shell' feature. Set the inside thickness to 3 mm to hollow out the bottle, making it functional for holding liquids.

6.1 Designing the Base Structure of the Cap

1. We selected the top face of the bottle's body and sketched a concentric circle with a diameter of 80 mm.
2. Then we extruded this circle to a height of 25 mm. This extrusion formed the base structure of the bottle cap.

Once the base structure for the cap was created, we temporarily hid this new body to allow us to continue working on the bottle without interference.

6.2 Adding important features to the bottle

1. Using the ' Thread ' feature, we added threads to the bottle's neck. These threads help the cap to screw on tightly, ensuring that the bottle stays leak-proof. Also, they make it easy to twist the cap open and shut, saving time and hassle.
2. After that, we decided to improve the bottle even further. We used the 'Filet' feature to round off the edge by 4 mm.

Once you're done with these steps, the bottle is ready!

We un-hid the cap body to start working on it.

7.1 Transfering Properties of the Bottle to the Cap

Utilizing the 'Combine' feature found within the 'Modify' options, we tried to copy the features of the bottle to the cap to ensure compatibility between the two components.

1. We set the bottle cap as the target body and the bottle as the tool body.
2. We opted for the 'Cut' option instead of the default 'Join' option. This allowed the cap to be modified to perfectly complement the bottle.
3. Additionally, by selecting the 'Keep Tools' option, we ensured that the threads of the bottle were transferred onto the cap.

7.2 Editing the So-Formed Cap

But now the modified cap had a prominent circle in its center. To address this, we chose the bottom face of this circle and extruded it to a depth of -20 mm. This helped us create ample space within the cap to accommodate the threads and ensure a snug fit between the cap and the bottle.

8.1 Making Room for Electronics

1. We selected the inner face of the cap's head and sketched a circle with a diameter of 40 mm.
2. Then, we extruded it by 20 mm, making sure it lined up with the bottom of the cap's sides.
3. Then, we selected the outer part of the cap's head and drew another circle, with a diameter of 38 mm.
4. We extruded this circle downwards by -20 mm, creating an area on top for fitting the electronics that would power the system.

This gave us a space inside the cap to place the electronics securely.

8.2 Making Space for the LEDs

1. We selected the base of the extruded circle and sketched two smaller circles, each with a diameter of 4 mm for the LED bulbs.
2. We kept each bulb at a distance of 12.5 mm from the center of the extruded circle.
3. To create holes for the LEDs, we selected these circles and extruded them. Instead of using the default 'Distance' option, we chose the 'to object' option and selected the upper face of this circle as the object.

This process resulted in two holes for each of the LEDs, ensuring they fit snugly into place.

With these adjustments made, the bottle cap was now fully equipped for use, ready to house the electronic components securely while still maintaining its functionality as a cap.

We went the extra mile and designed the electronics for this bottle cap. While these components can't function if 3D printed, they serve as an excellent resource for designing and brainstorming during CAD modeling, just as they were for us.

9.1 Designing the Solar Panel Enclosure

1. We began by sketching a circle with a diameter of 80 mm, matching the size of the solar panel we intended to use.
2. We extruded this circle to a height of 5 mm, creating a 3D shape capable of housing the solar panel.
3. To ensure a smooth fit and a more polished look, we added a 1 mm fillet to the top edge of the enclosure. This rounded the edges slightly, making it look circular.

9.2 Designing the Solar Panel

1. We designed a rectangle with very specific dimensions: 59.002 mm in length and 54.026 mm in width. These precise measurements were chosen to ensure that the solar panel would fit perfectly within its enclosure.
2. We extruded this rectangle to a height of 5 mm, giving it a solid 3D form.
3. All four corners of the 3D rectangle were then selected, and we applied a 2.5 mm fillet to each, rounding off the edges for a smoother finish.
4. Using the offset feature, we selected the entire top boundary of the rectangle and offset it inward by -1 mm.
5. This was then extruded downward by -0.2 mm to create a recessed area.
6. On this recessed face, we drew a smaller rectangle (50 mm by 0.5 mm), positioned 3.506 mm from the edge at the top.
7. This smaller rectangle was extruded to a height of 0.2 mm.
8. Using the rectangular pattern feature, we replicated this small rectangle eight times along a length of -49 mm, creating a series of identical extrusions.
9. On the same face, we created a vertical rectangle that passed through the centers of each smaller rectangle. This larger rectangle measured 53 mm in length and 1 mm in width, positioned 2.011 mm from the top and bottom edges of the face.
10. This vertical rectangle was also extruded to a height of 0.2 mm.

9.3 Assembling the Solar Panel

1. We inserted the designed solar panel into the circular enclosure we created earlier.
2. The panel was aligned with the base of the enclosure using the 'Align' feature to ensure a perfect fit.

By following these steps, we successfully created a solar panel. This process not only enhanced our design but also ensured proper planning and execution of our CAD model.

We designed the LEDs for our CAD modeling project using precise dimensions that match real LED lights. This makes our design useful for anyone looking to incorporate realistic LEDs into their models.

10.1 Designing the Base

1. We started by sketching a circle with a diameter of 5.90 mm.
2. From the center of this circle, we drew a vertical line extending 2.5 mm above and below the center point, creating a chord that intersects the circle.
3. We selected the larger segment of the circle, the area enclosed by the chord, and the circle's circumference.
4. This segment was then extruded to a height of 1 mm, forming the base of our LED.

10.2 Designing the Main Body

1. On the top face of the extruded base, we sketched another circle, this time with a diameter of 5 mm, centered on the same point as the original circle.
2. This smaller circle was then extruded upwards to a height of 7.5 mm, forming the main body of the LED.
3. We selected the top edge of this extruded cylinder and added a fillet with a radius of 2.5 mm. This rounded off the top, giving it the characteristic dome shape of an LED.

10.3 Creating the Pins

1. At the base of the LED, we drew two small squares, each with a side length of 0.5 mm.
2. These squares were positioned 1 mm away from the center of the circle on opposite sides.
3. The first square was extruded to a height of 25.6 mm, representing the longer lead of the LED, known as the anode. This lead should be connected to the positive terminal of the battery.
4. The second square was extruded to a height of 27 mm, representing the shorter lead, known as the cathode, which should be connected to the negative terminal of the battery.

With these steps completed, we had a realistic 3D model of an LED, ready to be used in our assembly and CAD modeling projects. The LED design was detailed and accurate, reflecting the dimensions and features of real LED lights.

Designing the bottle using CAD was a fun and educational experience. We started by brainstorming different types of bottles, considering options like curved bottles, gym bottles, and sippers. In the end, we decided that a regular, everyday bottle would best support our idea of promoting solar energy. So, we chose to design a sleek water bottle that can be used daily.

I learned a lot during this process. Creating threads for the first time and using the combine feature to fit the threads from one part to another was exciting. I always wondered how bottles have perfectly matching threads, and now I know. We also had to figure out how to add LED lights and a solar panel without making the bottle look bad. Adding small extrusions on the cap to hold the electronics was a simple but smart idea that improved our design a lot.

Making the CAD models for the solar panel and LED lights was another exciting part. It felt great to accurately model things that people use every day and see them fit perfectly into our bottle design. This was a big achievement for me and made our bottle both functional and stylish. The whole process was enjoyable and rewarding, and I learned new skills at every step.

Looking back, I really enjoyed the CAD design process and gained a lot of valuable experience. I learned many new techniques and concepts, which will help me with more challenging projects in the future. This project was an important step in my journey, providing both fun and learning opportunities.

12.1 Initial Plans

Initially, we planned to design our bottle following a tutorial on YouTube. This tutorial outlined the creation of a sipper-style bottle. However, we quickly realized that this design wasn't suitable for our specific needs. Sipper bottles have a small opening meant for drinking, which poses a challenge for our method of water sterilization using UV LED lights. The limited opening would make it difficult for the UV light to effectively sterilize the water, as it needs sufficient exposure to reach all the water inside the bottle.

12.2 Rethinking the Bottle Design

Understanding this limitation, we decided to explore a different bottle design that would better accommodate our UV sterilization method. We needed a bottle with a wider opening to ensure that the UV light could penetrate and sterilize the water effectively.

12.3 Future Plans for Sipper Bottles

Despite moving away from the sipper design for this project, we still see the immense potential of integrating UV sterilization technology into sipper bottles. In the future, we plan to develop a solution that allows us to incorporate this technology into sipper designs. This would make the technology more universal and convenient for a variety of bottle types.

13.1 3D Slicing and Software

We sliced the two STL files of the bottle and the cap separately using Ultimaker's Cura, a highly convenient and widely used software for slicing 3D prints. Cura's user-friendly interface and robust features make it an excellent choice for preparing models for printing. The bottle was sliced without supports, while the cap required a few supports to ensure proper printing.

13.2 Printing Process and Settings

The bottle took approximately 16 hours to print, slightly less than the estimated 18 hours. The cap, estimated at 5.5 hours, was completed in about 4.5 hours. Both parts were printed using our Anet ET4 Pro printer. The settings in Ultimaker Cura were set to "Normal," with a layer height of 0.15 mm and an infill percentage of 20% for both parts. These settings ensured a balance between print quality and speed.

14.1 Components Overview

The schematic for this project comprises a 6V 80mA solar panel and two UV LEDs. These LEDs emit ultraviolet light with a peak wavelength ranging from 390nm to 400nm, boasting a luminous intensity of 1000mcd. Their lens color is water-clear, ensuring efficient transmission of UV light.

14.2 Circuit Configuration

In the circuit configuration, the UV LEDs are connected in parallel with the solar panel, effectively utilizing it as a 480mAh battery pack. This design ensures a steady voltage of 6V across the UV LEDs while distributing the current between them evenly. This parallel connection not only simplifies the circuit but also optimizes power distribution for effective UV sterilization.

15.1 Soldering Process

To assemble the circuit, precise soldering techniques were employed. Small connecting jumper wires were utilized to establish the necessary connections between components. Careful attention was paid to ensure secure and reliable solder joints, minimizing the risk of electrical shorts or discontinuities.

15.2 Connection Layout

The positive terminal of the solar panel was meticulously linked to the positive terminals of both UV LEDs, while the negative terminal of the solar panel was similarly connected to the negative terminals of the LEDs. This parallel arrangement guarantees consistent power delivery to each UV LED, enhancing the overall reliability and performance of the water sterilization system. The systematic layout and attention to detail in making the connections contribute to the effectiveness and durability of the circuit.

15.3 Attach Solar Panel To Cap

After making the connections in the bottle cap based on the schematic, we attached the solar panel on top of the bottle cap. We used some hot glue to attach the solar panel. This ensures that the solar panel remains attached firmly and does not detach upon daily usage.

And there we have it—our completed solar-powered bottle that sterilizes its contents using ultraviolet light rays, providing an efficient and sustainable solution for clean drinking water. By harnessing solar energy, the bottle is both renewable and self-sufficient, making it ideal for areas without reliable access to electricity. Designed for the Green Future contest on Instructables, this project showcases the potential of integrating simple, effective technologies with renewable energy sources, marking a crucial step towards environmental sustainability and reducing reliance on non-renewable resources.

This innovative bottle addresses the global challenge of access to clean drinking water by combining UV sterilization and solar power. It offers a practical, scalable, and accessible solution that can significantly impact communities, particularly in remote and underserved areas. The solar-powered UV sterilization bottle embodies the principles of innovation, sustainability, and practicality, contributing to a greener and healthier future.

17.1 Enhancing Efficiency and Power Output

Looking ahead, our focus lies on improving the efficiency and power output of our solar-powered UV sterilization water bottle. We aim to increase the UV intensity closer to the ideal 16mW/cm² by integrating higher-efficiency solar panels and more powerful UV LEDs. Additionally, we are exploring advanced materials and coatings for the bottle that could reflect UV light more effectively, maximizing sterilization power without increasing energy consumption.

17.2 Expanding Application for Community-Level Impact

Beyond individual use, we envision scaling up the UV sterilization system for community-level water purification projects, particularly in remote and underserved regions. We plan to work on designing larger, solar-powered purification units capable of serving entire villages or communities. These units will maintain the core principles of our bottle—portability, self-sufficiency, and sustainability—while addressing the broader challenge of providing safe drinking water on a larger scale. Through these initiatives, we aim to make a significant impact on global water safety and sustainability.

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