Design of an Evanescent Waveguide Sensor Based on a-Si:H Photodiodes for Lab-on-Chip Applications

  • Alessio Buzzin
  • Rita Asquini
  • Domenico Caputo
  • Giampiero de Cesare
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 457)


Here we present the design of an amorphous silicon photodetector integrated with an ion-exchanged waveguide on the same glass substrate in order to obtain an evanescent waveguide sensor for on-chip biomolecular recognition in Lab-on-Chip applications. We studied the behaviour of a monochromatic light in a channel waveguide and its coupling into the thin-film sensor, using COMSOL Multiphysics. Simulations show that the presence of the photodiode’s insulation layer and transparent electrode strongly affects the coupling efficiency between the waveguide and the sensor.


Amorphous silicon photodiodes Evanescent waveguide sensor Waveguides SU-8 ITO Lab-on-Chip 


  1. 1.
    Caputo, D., Ceccarelli, M., de Cesare, G., Nascetti, A., Scipinotti, R.: Lab-on-glass system for DNA analysis using thin and thick film technologies. Mater. Res. Soc. Symp. Proc. 1191, 53–58 (2009)CrossRefGoogle Scholar
  2. 2.
    De Venuto, D., Vincentelli, A.S.: Dr. Frankenstein’s dream made possible: implanted electronic devices. Proc. of Design, Automation and Test in Europe DATE2013, art. no. 6513757, pp. 1531–1536 (2013)Google Scholar
  3. 3.
    Jung, W.E., Han, J., Choi, J.-W., Ahn, C.H.: Point-of-care testing (POCT) diagnostic systems using microfluidic lab-on-a-chip technologies. Microelectron. Eng. 132, 46–57 (2015)CrossRefGoogle Scholar
  4. 4.
    De Venuto, D., Carrara, S., Riccò, B.: Design of an integrated low-noise read-out system for DNA capacitive sensors. Microelectron. J. 40(9), 1358–1365 (2009)CrossRefGoogle Scholar
  5. 5.
    Costantini, F., Nascetti, A., Scipinotti, R., Domenici, F., Sennato, S., Gazza, L., Bordi, F., Pogna, N., Manetti, C., Caputo, D., de Cesare, G.: On-chip detection of multiple serum antibodies against epitopes of celiac disease by an array of amorphous silicon sensors. RSC Advances 4, 2073–2080 (2014)Google Scholar
  6. 6.
    Fixe, F., Chu, V., Prazeres, D.M.F., Conde, J.P.: An on-chip thin film photodetector for the quantification of DNA probes and targets in microarrays. Nucleic Acids Res. 32, e70–e75 (2004)CrossRefGoogle Scholar
  7. 7.
    Estevez, M.C., Alvarez, M., Lechuga, L.M.: Integrated optical devices for lab-on-a-chip bio-sensing applications. Laser Photonics 6, 463–487 (2012)CrossRefGoogle Scholar
  8. 8.
    Schmitta, K., Schirmera, B., Hoffmanna, C., Brandenburga, A., Meyrueisb, P.: Interferometric biosensor based on planar optical waveguide sensor chips for label-free detection of surface bound bioreactions. Biosens. Bioelectron. 22, 2591–2597 (2007)CrossRefGoogle Scholar
  9. 9.
    Asquini, R., d’Alessandro, A.: Tunable photonic devices based on liquid crystals and composites. In: Liquid Crystals XVII, Proc. of SPIE, SPIE Optics + Photonics, Organic Photonics and Electronics, 25–29 August 2013, San Diego, California, vol. 8828, pp. 88280T (1–14) (2013)Google Scholar
  10. 10.
    Gizzi, C., Asquini, R., d’Alessandro, A.: A polarization independent liquid crystal assisted vertical coupler switch. Mol. Cryst. Liq. Cryst. 421, 95–105 (2004)CrossRefGoogle Scholar
  11. 11.
    Gilardi, G., Asquini, R., d’Alessandro, A., Beccherelli, R., De Sio, L., Umeton, C.: All-optical and thermal tuning of a Bragg grating based on photosensitive composite structures containing liquid crystals. Mol. Cryst. Liq. Cryst. 558(1), 64–71 (2012)CrossRefGoogle Scholar
  12. 12.
    Zou, J., Zhao, F., Chen, R.T.: Two-step K+–Na+ and Ag+–Na+ ion-exchanged glass waveguides for C-band applications. Appl. Opt. 41, 7620–7626 (2002)Google Scholar
  13. 13.
    Gizzi, C., Asquini, R., d’Alessandro, A.: An integrated 2 × 2 SSFLC optical switch with channel ion-exchanged glass waveguides. Ferroelectrics 312, 31–37 (2004)Google Scholar
  14. 14.
    Asquini, R., d’Alessandro, A.: Bistable optical waveguided switch using a ferroelectric liquid crystal layer. In: Proc. IEEE LEOS 2000 13th Annual Meeting, 13–16 November 2000, vol. 1, pp. 119–120 (2000)Google Scholar
  15. 15.
    Zangheri, M., Di Nardo, F., Mirasoli, M., Anfossi, L., Nascetti, A., Caputo, D., de Cesare, G., Guardigli, M., Roda, A.: Chemiluminescence lateral flow immunoassay cartridge with integrated amorphous silicon photosensors array for human serum albumin detection in urine samples. Anal. Bioanal. Chem. 408(30), 8869–8879 (2016)CrossRefGoogle Scholar
  16. 16.
    de Cesare, G., Caputo, D., Tucci, M.: Electrical properties of ITO/crystalline silicon contact at different deposition temperatures. IEEE Electron Devices Letters 33(3), 327–329 (2012)CrossRefGoogle Scholar
  17. 17.
    Caputo, D., de Cesare, G., Scipinotti, R., Stasio, N., Costantini, F., Manetti, C., Nascetti, A.: On-chip diagnosis of celiac disease by an amorphous silicon chemiluminescence detector. Lect. Notes Electr. Eng. 268, 183–187 (2014)CrossRefGoogle Scholar
  18. 18.
    Caputo, D., de Cesare, G., Nascetti, A., Tucci, M.: Improving the stability of amorphous silicon ultraviolet sensor. Thin Solid Films 515, 7517–7521 (2007)CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG 2018

Authors and Affiliations

  • Alessio Buzzin
    • 1
  • Rita Asquini
    • 1
  • Domenico Caputo
    • 1
  • Giampiero de Cesare
    • 1
  1. 1.Department of Information Engineering, Electronics and TelecommunicationsUniversity of Rome “La Sapienza”RomeItaly

Personalised recommendations