Two-dimensional multi-channel neural probes with electronic depth control

Tom Torfs, Arno A.A. Aarts, Mehmet A. Erismis, Junaid Aslam, Refet Firat Yazicioglu, Karsten Seidl, Stanislav Herwik, Istvan Ulbert, Balázs Dombovari, Richárd Fiáth, Bálint Péter Kerekes, Robert Puers, Oliver Paul, Patrick Ruther, Chris Van Hoof, Herc P. Neves

Research output: Contribution to journalArticle

43 Citations (Scopus)


This paper presents multi-electrode arrays for in vivo neural recording applications incorporating the principle of electronic depth control (EDC), i.e., the electronic selection of recording sites along slender probe shafts independently for multiple channels. Two-dimensional (2D) arrays were realized using a commercial 0.5-μm complementary-metal-oxide-semiconductor (CMOS) process for the EDC circuits combined with post-CMOS micromachining to pattern the comb-like probes and the corresponding electrode metallization. A dedicated CMOS integrated front-end circuit was developed for pre-amplification and multiplexing of the neural signals recorded using these probes. 2D arrays with IrOx metal finish showed electrode impedances of 300 kΩ on average with a standard deviation of 175 kΩ. In vivo tests demonstrated the capability to simultaneously record multi-unit activity in addition to local field potentials on each of the available output channels using the electronic depth control circuitry, and to finely adjust the position of the recording sites along the probe shaft for an optimal signal-to-noise ratio. In addition, this depth control concept has been demonstrated in the electronic steering of electrodes selected simultaneously within thalamic sites in the rat. By enabling the selection and thus position fine-tuning of the individual recording sites after implantation, this new device significantly increases the amount of useful information that can be obtained from a single recording experiment.

Original languageEnglish
Article number5999737
Pages (from-to)403-412
Number of pages10
JournalIEEE Transactions on Biomedical Circuits and Systems
Issue number5
Publication statusPublished - Oct 1 2011



  • Complementary-metal-oxide-semiconductor (CMOS) integrated circuits
  • implantable biomedical devices
  • multi-electrode arrays
  • neural probes

ASJC Scopus subject areas

  • Biomedical Engineering
  • Electrical and Electronic Engineering

Cite this

Torfs, T., Aarts, A. A. A., Erismis, M. A., Aslam, J., Yazicioglu, R. F., Seidl, K., Herwik, S., Ulbert, I., Dombovari, B., Fiáth, R., Kerekes, B. P., Puers, R., Paul, O., Ruther, P., Van Hoof, C., & Neves, H. P. (2011). Two-dimensional multi-channel neural probes with electronic depth control. IEEE Transactions on Biomedical Circuits and Systems, 5(5), 403-412. [5999737].