1. Optical Biosensors Joel Kindt Lauren Netherton Acknowledgements Dr. Kevin Lear Dr. Dave Kisker Weina Wang Hailey Cutler 1

2. Lauren Netherton Motivation and Introduction Prior Research How Optical Biosensors Work 2

3. “60% of Golden Retrievers Die of Cancer” “1 in 4 Dogs Will Die of Cancer” -Morris Animal Foundation 3 Courtesy of Kian Behbakht of UC Denver

4. Prior Research Senior Design Team 2007-2008 4

5. Pipe Organ Analogy Place fruit in organ pipe Changes pitch based on: –Size –Shape http://lib.colostate.edu/archives/phelps/ 5

6. 6 Optical Detection & RF Switch Circuit Spectrometer Healthy Cancerous! Courtesy of Weina Wang

7. Trapping Requirements Lower voltages –Trap at slower velocity Higher voltages –Trap at higher velocity 7

8. Dielectrophoretic Force Use of electromagnetics Non-uniform electric field –Polarizes molecules within cell –Induces DEP force to hold cell in trap Electric field 8 December 2007 Senior Design Presentation

9. Polarization factor (K factor): Complex permittivity of particle/suspending medium: Dielectrophoretic Force 9 Courtesy of Weina Wang

10. Joel Kindt Electrostatic Modeling Experimental Data Budget Conclusions and Future Work 10

11. Electrodes on Chip 11

12. Electrostatic Modeling 12

13. DEP ForceE-Field 13

14. Positive and Negative DEP Mammalian white blood cell σ m = 0.1 S/m (~ water) σ m = 1.5 S/m (~ PBS) Joel Voldman, “Electrical Forces For Microscale Cell Manipulation”, Annu. Rev. Biomed. Eng. 2006. 8:425-54 14 Polarization factor (K factor):  K > 0: Positive DEP  K < 0: Negative DEP,

15. Experimental Setup 15

16. Impedance of Channel Voltage Divider http://en.wikipedia.org/wiki/Voltage_divider 16

17.  more heat dissipated at lower impedance 17 Impedance of Channel

18. Budget Materials1 st semester budget 1 st semester actual 2 nd semester budget Syringes$15$0$15 Glass$75$0 Nanoports$0 $60 Nanotubing$0 $25 Flexible mirror$10$0 Total$100$0$100 18

19. Know trapping requirements for various fluid velocities Possible to model cell trap through simulations –Electric field –DEP force The fluid properties can affect results –K factor –Impedance of channel 19 Conclusions

20. Design better cell trap through simulations Further understand spectra –Cancerous vs. non-cancerous cells –Different types of cancer Save Rover! 20 Future Work