Nanotechnology in Secondary Science Classroom: Modeling a Gas Sensor

1. Nanotechnology in Secondary Science Classroom: Modeling a Gas Sensor Elena Cox, Ph. D., Curriculum & Instruction, Texas A&M University, Commerce The 7th Annual Texas STEM Conference Dallas February 6, 2014

2. Introduction • Research Experience for Teachers (RET) program at Georgia Institute of Technology • Research team at Mechanical Engineering worked with developing and designing microelectromechanical gas sensors

3. Clean room • Air • Clothing • Rules of behavior and safety • Introduction to the latest equipment and advances in science and technology available in the area of nanotechnology.

4. Microelectronic Fabrication • Micro gas sensors are fabricated on silicon wafers which I saw there for the first time.

5. Microelectronic Fabrication • One thing is to see the pictures of computer chips in textbooks, and another thing is to actually to learn how to make them yourself.

6. Microelectronic Fabrication • The professor in charge of the research team has more than 200 patents and supervises a research group of graduate students, always found the time to introduce me to microelectronic fabrication and to teach me how to work with silicon wafers.

7. Basics of Photolithography • Most of the time during the Summer RET program was spent learning about and working with nano photolithography

8. Basics of Photolithography As a part of research team, I was allowed to work in a clean room performing the following operations: • Spinning of photoresist:

9. Basics of Photolithography • Aligning the mask:

10. Basics of Photolithography • Developing photoresist:

11. Basics of Photolithography • The pattern quality check by using profilometer and a microscope:

12. Basics of Photolithography • Chemical and plasma etching

13. Basics of Photolithography • Cutting the wafer and glass bonding:

14. Basics of Photolithography • All this work was required to manufacture a gas chromatographic column less than 1/3 of an inch but 2 meters long.

15. Chemistry TEKs (4)  Science concepts. The student knows the characteristics of matter and can analyze the relationships between chemical and physical changes and properties. The student is expected to: (D)  classify matter as pure substances or mixtures through investigation of their properties.

16. Gas Chromatograph: Separation of Mixtures http://en.wikipedia.org/wiki/Gas_chromatography

17. Gas Chromatograph

18. Macro-scale Gas Chromatographic Column

19. Gas Chromatographer Video

20. Miniaturized Gas Chromatographic Column on Silicon Wafer 2 cm

21. SEM of a DRIE etched silicon microchannel of GC. Noh et al., 2002

22. SEM images of a parylene-coated silicon microchannel. Noh, 2004

23. Column geometry. Parylene column (middle) and parylenecolumn with heat diffuser (right) Noh et al., 2002

24. Introducing Nanotechnology by Modeling the Gas Sensor • I could talk to students about the properties of atoms in more detail because I was working with structures on atomic level. • I was able to develop a lesson plan and conduct a lesson based on the knowledge I gained during RET on chromatography pertaining in a separation of mixtures unit.

25. Chromatography Concept and Chemistry TEK 4d The chromatography lesson was presented at teacher conferences in Washington and San Francisco.

26. Modeling Gas Nano-Sensor at Texas A&M University: Project-Based Learning in STEM classroom

27. Modeling Gas Nano-Sensor at Texas A&M University: Project-Based Learning in STEM classroom

28. Modeling Gas Nano-Sensor at Texas A&M University: Project-Based Learning in STEM classroom

29. Modeling Gas Nano-Sensor at Texas A&M University: Project-Based Learning in STEM classroom

30. Candy Chromatography: Modeling a Gas Sensor In your bag: small bowl coffee filters droppers Plate 2 Clear drinking glasses filled with water Drinking glass filled with salt water Skittles, Gobstoppers, M&M's Ruler Pencil Food colors Silica gel

31. Food Colors Separation • Put silica gel into one of the clear glasses filled with water. Wait for about 1 minute for crystals to absorb water.

32. Food Colors Separation • Put silica gel into one of the clear glasses filled with water. Wait for about 1 minute for crystals to absorb water. • Using dropper, put several drops of food color mixture on the silica gel after it increase in size.

33. Food Colors Separation • Put silica gel into one of the clear glasses filled with water. Wait for about 1 minute for crystals to absorb water. • Using dropper, put several drops of food color mixture on the silica gel after it increase in size. • Pour some water over the silica gel/the drops.

34. Food Color Separation

35. Food Color Separation • What do you observe? • What food colors were mixed?

36. Food Color Chromatography • Take the unused tall clear glass filled with water covering the bottom of the glass.

37. Food Color Chromatography • Take the unused tall clear glass filled with water covering the bottom of the glass. • Take a strip of filter paper. Roll it over the Q-tip

38. Food Color Chromatography • Take the unused tall clear glass filled with water covering the bottom of the glass. • Take a strip of filter paper. Roll it over the Q-tip • Using a pencil and a ruler, draw the line about ¼” from the edge of the paper • Mark a dot where you will put your separation mixture with a pencil

39. Food Color Chromatography • Take the unused tall clear glass filled with water covering the bottom of the glass. • Take a strip of filter paper. Roll it over the Q-tip • Using a pencil and a ruler, draw the line about ¼” from the edge of the paper • Mark a dot where you will put your separation mixture with a pencil

40. Food Color Chromatography • Using a dropper, put one drop of a food color mixture on the dot on the filter paper

41. Food Color Chromatography • Carefully place the Q-tip with filter paper inside your glass with water. • Wait for the water to start rising on the filter paper.

42. Food Color Cromatography

43. Food Color Chromatography • What changes of your dot do you observe? • What colors do you think were mixed together? Can you tell the difference between colors?

44. Candy Chromatography • Take out a dinner plate and lay one of each color of Skittles, leaving a little space around each one.

45. Using a pipette or dropper, squeeze a little water onto each piece of candy to start dissolving the shell.

46. While you wait for the candy to dissolve, draw a pencil line about 2 cm from the bottom edge of the paper. Do not use pen, because the ink will run. This is your origin line.

47. When the water around the candy has turned color, squeeze the colored water into the pipette bulb.

48. Drop a few drops of colored water on the origin line on your filter paper. You may need to add several drops to ensure you have enough dye. 

49. Repeat this with each color, leaving about 2 cm between each color

50. Let the filter paper dry completely.