Applications and Implications¶
H2Lyte Sense | H2-Electrolyte Quality Test Kit¶
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¶
At Fab Lab Bali, the Hydrogen Village project aims to empower the local community through the development of green hydrogen technology. One research focus is identifying safe, environmentally friendly catalyst solutions to enhance the electrolysis process, effectively producing hydrogen gas. The goal is to develop a practical, cost-effective, and environmentally friendly catalyst using locally sourced materials like tofu wastewater, pineapple juice, and activated charcoal from coconut waste.
H2Lyte Sense is intended as a portable, low-cost meter device for researching non-toxic catalysts suitable for Serangan Village. It aims to incorporate local everyday objects, such as glass jars, as part of the design, promoting citizen science and community involvement in finding non-toxic catalysts for hydrogen electrolysis.
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.
However, for the first prototype (spiral 1) I will just focus on measuring various parameters to find the effective local-based, catalyst, e.g EC, pH Levels, Temperature.
Precedents¶
Previous FA Student
Handmade Sensors
Packaging Inspirations
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¶
