Engineering World Health

A Colorimetric Luminescent Oxygen Sensor Using a Green LED with Pt Octaethlyporphyrin as the Oxygen-

Responsive Element.

Goals

Design and develop an oxygen sensor that is safe, robust, and relatively inexpensive to produce and operate.

The colorimetric oxygen sensor should be able to differentiate between 95% oxygen concentrated air and 22% oxygen concentrated ambient air.

The device must be easy to assemble by Engineering World Health volunteers.

Project Status

Prototype Fabricating and Testing Budget

Polymer Composite Parts Cost

Platinum Octaethylporphyrin (100 mg) x 2 $412.00

Zinc Oxide (250 g) $53.70

Ethyl Cellulose (250 g) $77.10

Diazabicyclooctane (500 g) $146.50

Tetrahydrofuran (1 L) $83.00

Casing Parts Cost

RapidTech Casing – Hard Plastic $300.00

Plastic Primer and Paint $20.00

Temporary Testing Case $24.50

LED Flash Lamp Parts Cost

Green LED (10mm) $4.50

LED Breakout Kit $8.95

Color and Intensity Sensor Parts Cost

TEMT6000 Breakout Board Light Sensor $4.50

Color Light Sensor Board $8.95

Wall Power Supply 5V $8.00

Breadboard Power Supply $10.00

Customized PCB x 3 $45.00

Total Budget with Other Miscellaneous Expenses

$1,555.00

• Jay Patel (Leader)

• Marvin Patel• Nirav Shah

• Andrew Do (Leader)

• Jay Patel• Marvin Patel

•Nirav Shah (Leader)•Andrew Do•Sapphire Lopez•Justin Akiyama

• Marvin Patel (Leader)

• Justin Akiyama• Sapphire Lopez

Team Organization

January – March 2011: Budget revision and design components fabrication.

April – June 2011: Testing and revising prototype. Evaluating results and user-feedback.

Casing

LED Flash Lamp

Polymer Composite

Color &Intensity

Sensor

Summary

References

Our oxygen analyzer is different from other similar oxygen analyzers in the market because it will not require constant calibration and maintenance. Furthermore our device, with an estimated market of 50,000 devices, will be fairly inexpensive to mass manufacture and durable for non-profit distribution in third world countries. The estimated mass production cost of the casing and electronics is $10, and an additional $10 for the polymer composite.

System Design

Polymer composite: Porphyrin encapsulated in cellulose along with stabilizers and scattering agents.

Goal: To design a thin composite that lowers the stabilization time for the emissions and does not degrade rapidly, thereby, maximizing the lifespan of the composite (Figure 1).

Casing: Houses all of the electronics and the polymer composite, and serves as a black box.

Goal: To design a casing that is durable, user friendly, easy to assemble, and sufficiently black-boxed.

LED flash lamp: A cluster of three super bright green LEDs, which initiate the reaction between the porphyrin and oxygen.

Goal: To design a flash lamp that provides a reliable source of high intensity of green light to activate the porphyrin. Furthermore, it must be durable and long lasting.

Color and Intensity sensor: Measures the wavelength and intensity of the emission from the polymer composite and correlates them to an oxygen concentration.

Goal: To design a sensor which can measure the wavelength and intensity of the emissions, and process the information to correlate it to an oxygen concentration (Figure 1, 2).

[1] Beard, Melissa. "Engineering World Health." EWH, n.d. Web. 28 OCT 2010. <http://ewh.org/index.php/programs/technology/competition/>.

[2] Ricketts, S R. (2008). A simple colorimetric luminescent oxygen sensor using a green LED with Pt octaethylporphyrin in ethyl cellulose as the oxygen-responsive element. Sensors and actuators. B, Chemical, 135(1), 46-50.

[3] Evans, R C. (2009). Design and Color Response of Colorimetric Multilumophore Oxygen Sensors. ACS applied materials & interfaces, 1(5), 1023-1030.

Figure 2: Emission spectra at different partial pressures O2.

Marvin Patel, Jay Patel, Nirav Shah, Andrew Van Do, Justin Akiyama and Sapphire LopezAdvisors: Dr. William Tang, Mindy Simon and Meghan Cozzens

University of California, Irvine and Engineering World Health

Figure 1: A schematic of sensor design