Final Project: H2Lyte Sense¶
H2Lyte Sense is a low-cost test instrument kit designed to measure the performance of an electrolyte solution for green hydrogen catalyst research. It measures electrical conductivity, TDS (Total Dissolved Solids), temperature, and pH levels of an aqueous solution using a DIY sensor probe, with readings displayed on an OLED sensor controlled via a rotary encoder.
Context¶
Hydrogen Village¶
At Fab Lab Bali, we have a Hydrogen Village project which aims to empower the local community through green hydrogen technology development. One of the research lines is to find a safe, environmentally friendly catalyst solution that will aid or accelerate the electrolysis process in order to produce the most amount of hydrogen gas effectively.
This research was initially proposed by Cesar Jung-Harada from the Singapore Institute of Technology, and in collaboration with Prof. Ni Made Dwidiani, a Material Science expert from Udayana University. We aim to develop an environmentally friendly catalyst based on her previous research on utilising locally sourced organic waste materials, such as tofu wastewater, pineapple juice, activated charcoal from coconut waste, etc.
Problem Statement¶
To do this, we have to carry out many hydrogen experiments with these different materials and formulations. However, setting up one hydrogen experiment alone is already tricky and can take quite some time. And in the process, there is quite a long lead time when we have to wait for the hydrogen to produce the gas bubbles. All these things are done only for us to know which of these liquid formulations have the most conductivity and can produce the most hydrogen in the shortest time. So it is not really practical to set up the hydrogen experiment every time, and it will take a very long time for us to monitor and measure the hydrogen production, let alone to carry out and test many different material formula options.
- Measurement challenges
- Lack of practicality of conducting green-catalyst experiments
- Time-intensive process for setup, execution, and long-lead time when waiting for results (waiting for gas bubbles)
- Potential toxic chemicals as by-product of the electrolysis process
To sum up, it’s difficult and takes a long time to set up the instruments for researching environmentally-friendly catalyst for green hydrogen production
Initial Idea¶
The idea is to make a portable and low-cost meter device for green hydrogen’s non-toxic catalyst research that is suitable for local context of Serangan Village by incorporating local everyday objects, in this case the classic glass jars that everyone has in their homes, and can be used as an educational tool and promote citizen science movement to encourage participation from the local community in finding the non-toxic catalyst for green hydrogen electrolysis process.
Goals¶
- To measure various parameters to find the effective non-toxic, local-based, catalyst, e.g EC, pH Levels, Temperature, Contaminants
- To measure toxicity levels for toxic chemical management and safe disposals
- Furthemore, the system can be embedded as well at the main hydrogen generator detect/measure the toxicity levels as a result of the electrolysis process
- Can be used as an educational toolkit for the communities, to promote citizen science movement, making science experiments less intimidating to the locals
- Moreover, can be used to monitor water quality for other purposes in the Hydrogen Village, e.g aquaculture, hydroponic, etc.
References¶
- Open Funk
- Low Cost Milk Liquid Food Quality Checker by Muhammad Prasetya Kurniawan - FA 20222
- Hacking local everyday objects with 3D printer
Questions need to be answered¶
- How to effectively measure the performance of electrolyte? What parameters need to be measured?
- How might we make the device cost-effective and easy to use and/or replicate>
- How accurate and reliable are the DIY sensor probes for measuring EC, TDS, temperature, and pH levels?
- What are the power requirements for the device, and how will it be powered (e.g., battery, USB)?
- Can the device be easily assembled and maintained by community members with minimal technical expertise?
- Will the OLED display and rotary encoder interface intuitive and easy to use for displaying and controlling sensor readings?
Design Overview¶
Since this device is intended for community use, the design will be as frugal as possible, using basic digital fabrication tools, including 3D printers, laser cutters, and precision milling machines, and utilizing locally available materials. This ensures the project can be easily reproduced in various locations, especially benefiting coastal communities.
The device measures electrical conductivity, TDS, temperature, and pH levels of an aqueous solution using a DIY sensor probe, with readings displayed on an OLED sensor controlled via a rotary encoder.
Electronics System¶
Components:
Input Devices
- NTC Thermistor 10K 3435
- Electric Conductivity + TDS Sensor (DIY) using 1k resistor resistor
- Rotary Encoder
- pH Sensor (further development)
Output devices
- OLED SH1106 12C 1.3"
MCU
- SeeedStudio Xiao XIAORP2040
System Diagram
The design will include a custom PCB tailored for this project.
3D Design System¶
Enclosure¶
Built upon my initial idea of wanting to incorporate everyday glass jars that people have in their home, and with modularity system in mind, the device’s enclosure consists of two main parts: the main controller unit body and the probe storage.
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Controller unit body:
The main controller unit body comprises two parts:
- Probe Storage
Initially, the plan is to utilize a glass jar or any existing bottle for probe storage. However, due to the long dimensions of the pH sensor probe, finding a suitable size is challenging. For the first prototype, this part will be 3D printed.
Sensors Probe Design¶
I also will design and made the probe by myself by laser-cutting it with press-fit joineries.
System Integration¶
All module parts, including the controller unit cap, body, and probe storage, will be connected using a twist-lock mechanism. The enclosure will be 3D printed with PLA, applying a fuzzy skin texture in the slicer settings to minimize visibility of 3D printing seams on round shapes.
The sensor probe will be designed frugally using a stainless steel rod, integrated into a voltage divider circuit with the MCU input voltage. It will be fabricated using laser-cutting and press-fit joineries.
The overall integration will use a combination of press-fit joinery, twist-lock mechanisms, brackets, and screws for assembly.
Bill of Materials¶
| Category | Components (unit) | Price/Unit | Quantity | Total Price |
|---|---|---|---|---|
| Microcontroller | Seeed Studio XIAO RP2040 | Rp115,000 | 1 | Rp115,000 |
| Input Devices | NTC Thermistor 10K 3435 Waterproof | Rp15,000 | 1 | Rp15,000 |
| RES SMD 10K OHM 1% 1/4W 1206 | Rp100 | 1 | Rp100 | |
| RES SMD 1K OHM 1% 1/4W 1206 | Rp150 | 1 | Rp150 | |
| PH-4502C Sensor with Probe Electrode (not used yet) | Rp219,000 | 1 | Rp219,000 | |
| KY-40 Rotary Encoder | Rp6,500 | 1 | Rp6,500 | |
| Output Devices | OLED I2C Display 1.3” White | Rp45,700 | 1 | Rp45,700 |
| PCB Production | FR1 Board 10x10cm | Rp4,000 | 1 | Rp4,000 |
| Male Vertical Pin Header 2.54mm Pitch | Rp250 | 27 | Rp6,750 | |
| Resistor 0 OHM 1206 | Rp100 | 3 | Rp300 | |
| Power Supply | Lithium-ion Polymer Battery 3,7V 2000mAh | Rp98,750 | 1 | Rp98,750 |
| Enclosure | PLA Filament | Rp279 /g | 270 g | Rp75,330 |
| Probe | Acrylic sheet 3mm | Rp23 /cm2 | 40 cm2 | Rp920 |
| Stainless Steel Rivet | Rp1,500 | 2 | Rp3000 | |
| Seal O-ring rubber - 10mm | Rp563 | 3 | Rp1,689 | |
| Heat shrink tube 14 mm - white | Rp99,5/cm | 10 cm | Rp995 | |
| Signal cable 26 AWG (cm) | Rp9,900 | 20 | Rp1,980 | |
| System Integration | M3 Screw - 6 mm | Rp400 | 16 | Rp6,400 |
| Panel Connector (4 pin) | Rp6,000 | 1 | Rp6,000 | |
| Total | Rp607,564 |
The total cost for this project is Rp607,564 or around USD37. However, this BOM above is made in the context if every sensors designed here are used. But in my case, for the final project, I haven’t programmed and use the pH sensor yet. Withouth pH sensor, the cost would be Rp388,564 or around USD 23,75.
Evaluation¶
- Reading Accuracy: compare sensor readings with those from standard commercial sensors under controlled conditions
- Usability: Assess the ease of assembly, calibration, and operation for non-technical users.
- Durability: Test the physical durability of the 3D-printed enclosure and the reliability of the electronic components over time.
- Cost Effectiveness: Compare the total cost of the device against similar commercial products and assess its affordability for the community.
- Educational Impact: Measure the effectiveness of the device as an educational tool for promoting citizen science.
- Scalability: Determine the ease with which the device can be reproduced and deployed in other communities.
Further Development¶
Related Weekly Page¶
- Week 2: Computer Aided Design
- Week 9: Output Devices
- Week 11: Input Devices
- Week 13: Embedded Networking and Communication
- Week 14: Interface and Application
- Week 17: Applications and Implications
- Week 18: Invetion, IP and Income
Files¶
License¶
This project will be registered under a Creative Commons License CC BY-NC-SA
Credits¶
- Thank you so much to my colleague, Eka and Elaine, without them I will not be able to survive Fab Academy!❤️
- Next, thank you (wouldn’t be enough) to Rico Kanthatam from Skylab Workshop and Kurumi Shiowaki, our amazing instructor and facilitator, for their extra patience🥹 and rigor in making sure we’re here to this point.
- Thank you so much to Tomas encouraging me to take Fab Academy, and trusting us, and always have our back! We’re soo lucky!
- Thank you to Fab Lab Bali, Meaningful Design Group, and CAST Foundation – the place where I work which provide me with this wonderful opportunity to learn sooooo much and has been very supportive in our development!
- Thanks to BRIN for being our consulting expert
- Finally, thank you so much to ViriyaENB for sponsoring me and my other colleagues for this training..
And many more!