2. OUTLINE
• Introduction
• The Team
• What is a biosensor?
• Structure of a Biosensor
• Our Design
• Training
• Software/Programs
• The Lab
• Research
• Laser Diodes
• Spectrometer
• CMOS Camera
• Testing and Conclusions
• Laser Diode Stability Test
• Contributions and Experience

4. THE TEAM: SUPERVISOR AND
GRADUATE STUDENTS
Supervisor:
 Dr. Seung Kim
 Assistant Professor of Electrical
Engineering since 2010
 Senior researcher at BYU from
2004-2010
 Ph.D., University of Alabama,
Huntsville, 2004
 B.S., University of Suwon, Korea,
1998
Graduate Students:
 SaiHim Cho
 Electrical Engineering
 Cody Joy
 Electrical Engineering

5. Undergraduates:
Rebekah Cushman
 Computer Engineering
Gino Chacon
 Computer Engineering
Jonathan Herbert
 Electrical Engineering
High School Students:
Robin Kim:
 Spring Hill HS
Katy O’Quinn:
 Hallsville HS
Cydnie Robison:
 Longview HS
THE TEAM: UNDERGRADUATE AND HIGH
SCHOOL STUDENTS

6. WHAT IS A BIOSENSOR?
Device for sensing chemical
and biological material
Our goals:
 Point of care
 Rapid analysis
 Multiplexible
 Portable
 Cost effective

7. STRUCTURE OF A BIOSENSOR

8. THREE LASER DESIGN
λ3
780 nm
CMOS
Camera
Optical Cavity
Sensing Layer
Δd
λ1
830 nm
λ2
850 nm

10. TRAINING

11. SOFTWARE/PROGRAMS THAT I HAVE USED
FOR RESEARCH
Project Forum
SolidWorks
IGOR Pro

12. PROJECT FORUM
• Used to keep up with
work
• Allowed other team
members to view
progress

13. SOLIDWORKS
• Used to create 3D models that
could be printed quickly for use
in the prototype

14. SOLIDWORKS FILTER DESIGN

15. IGOR PRO
• Takes in data
collected from
spectrometer or
CMOS camera
and turns data
into graphs

16. THE LAB

17. INSIDE THE LAB

18. FABRICATION
PROCESS

20. WHAT IS A LASER DIODE?
(KATY O’QUINN)
A laser diode is a component that
converts an electrical signal into a
corresponding light signal.
The most common type of laser diode
is a semiconductor laser diode.

21. LASER DIODES
A laser diode is a small inexpensive way of producing light
Discovered possibility of monitoring using photodiode
Gained better understanding of laser diodes

22. WHAT IS AN OPTICAL SPECTROMETER?
(ROBIN KIM)
Takes light and breaks it down into spectral components
Allows us to test stability of laser diodes

23. SPECTROMETER
• Discussed the
function of the
spectrometer, the
physical principles
behind it, and graphs
produced by
spectrometer
• Gave basic
knowledge in order to
do spectrometer tests

24. WHAT IS A CMOS CAMERA?
(CYDNIE ROBISON)
CMOS – Complimentary metal oxide
semiconductor
The CMOS camera calculates the change in the
laser’s light.

25. THE CMOS CAMERA
• Showed the
benefits and
shortcomings
of CMOS and
made CCD an
option

27. SETUP
Spectrometer
Exposure time: 0.1
ms
780nm, 830nm,
850nm laser diodes
on

28. LASER DIODE STABILITY TEST
Test the stability of the laser diodes over time
Measures absolute irradiance and wavelength of laser
diodes

29. DATA PROCESSING
Used Igor to attain information about the laser diodes based on the light
collected by the spectrometer.

30. DATA PROCESSING: WAVELENGTH AND
MAXIMUM ABSOLUTE IRRADIANCE

31. DATA PROCESSING: SUM OF IRRADIANCES

32. DATA PROCESSING: FULL WIDTH AT HALF
MAXIMUM

33. LASER DIODE STABILITY TEST RESULT I
The spectrometer test that used laser diodes with higher power
showed that the total maximum irradiance was more stable than
when the lasers had less power.

34. LASER DIODE STABILITY TEST RESULT II
As maximum absolute irradiance increases, FWHM
decreases.

35. LASER DIODE STABILITY TEST RESULT III
Wavelengths of lasers are not 780nm, 830nm, 850nm but are
rather 785nm, 832nm, and 863nm, respectively.

37. MY MAIN CONTRIBUTIONS TO THE BIOSENSOR
RESEARCH TEAM DURING THIS SUMMER 2014
 Individual Research
- Optical Spectrometer
 High School Students’ Research
-Laser Diode Stability Test Analysis

38. WHAT I HAVE LEARNED THROUGH THE BIOSENSOR
RESEARCH SUMMER PROGRAM AT LETOURNEAU
• Experienced the research environment
• Learned how to work as team
• Learned how to think like an engineer
• Learned how to use different software and programs
• Inspired me to major in electrical engineering