Vasiliki Giagka

Publications

  1. Wafer-scale Graphene-based Soft Implant with Optogenetic Compatibility
    A.I. Velea; S. Vollebregt; G.K. Wardhana; V. Giagka;
    In Proc. IEEE Microelectromech. Syst. (MEMS) 2020,
    Vancouver, Canada, IEEE, Jan. 2020.
    document

  2. Comments on “Compact, Energy-Efficient High-Frequency Switched Capacitor Neural Stimulator With Active Charge Balancing"
    Alessandro Urso; Vasiliki Giagka; Wouter A. Serdijn;
    IEEE Transactions on Biomedical Circuits and Systems,
    2019. DOI: 10.1109/TBCAS.2019.2898555
    document

  3. An Ultra High-Frequency 8-Channel Neurostimulator Circuit with 68% Peak Power Efficiency
    Alessandro Urso; Vasiliki Giagka; Marijn Van Dongen; Wouter A. Serdijn;
    IEEE Transactions on Biomedical Circuits and Systems,
    2019. DOI: 10.1109/TBCAS.2019.2920294
    document

  4. EMBEDDING SMALL ELECTRONIC COMPONENTS INTO TINY FLEXIBLE IMPLANTS
    Anna Pak; Wouter A. Serdijn; Vasiliki Giagka;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  5. TOWARDS AN ACTIVE GRAPHENE-PDMS IMPLANT
    Gandhika K Wardhana; Wouter A. Serdijn; Sten Vollebregt; Vasiliki Giagka;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  6. POLYMER-ENCAPSULATED SINGLE-CHIP IMPLANTS FOR BIOELECTRONIC MEDICINE
    Kambiz Nanbakhsh; Wouter Serdijn; Vasiliki Giagka;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  7. TOWARDS A SEMI-FLEXIBLE PARYLENE-BASED PLATFORM TECHNOLOGY FOR ACTIVE IMPLANTABLE MEDICAL DEVICES
    Nasim Bakhshaee Babaroud; Marta Kluba; Ronald Dekker; Wouter Serdijn; Vasiliki Giagka;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  8. THE INFLUENCE OF SOFT ENCAPSULATION MATERIALS ON THE WIRELESS POWER TRANSFER LINKS EFFICIENCY
    Anastasios Malissovas; Wouter A. Serdijn; Vasiliki Giagka;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  9. DESIGN AND CUSTOM FABRICATION OF A SMART TEMPERATURE SENSOR FOR AN ORGAN-ON-A-CHIP PLATFORM
    Martins da Ponte, Ronaldo; Vasiliki Giagka; Wouter A. Serdijn;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  10. DESIGN OF A MULTI-FUNCTIONAL SMART OPTRODE FOR ELECTROPHYSIOLOGY AND OPTOGENETICS
    Martins da Ponte, Ronaldo; Chengyu Huang; Vasiliki Giagka; Wouter A. Serdijn;
    In Book of Abstracts, 7th Dutch Biomedical Engineering Conf. (BME) 2019,
    Jan. 24-25 2019.
    document

  11. Pressure measurement of geometrically curved ultrasound transducer array for spatially specific stimulation of the vagus nerve
    S. Kawasaki; V. Giagka; M. de Haas; M. Louwerse; V. Henneken; C. van Heesch; R. Dekker;
    In Proc. IEEE Conf. on Neural Eng. (NER) 2019,
    San Francisco, CA, USA, March 2019.
    Abstract: ... Vagus nerve stimulators currently on the market can treat epilepsy and depression. Recent clinical trials show the potential for vagus nerve stimulation (VNS) to treat epilepsy, autoimmune disease, and traumatic brain injury. As we explore the benefits of VNS, it is expected that more possibilities for a new treatment will emerge in the future. However, existing VNS relies on electrical stimulation, whose limited selectivity (due to its poor spatial resolution) does not allow for any control over which therapeutic effect to induce. We hypothesize that by localizing the stimulation to fascicular level within the vagus nerve with focused ultrasound (US), it is possible to induce selective therapeutic effects with less side effects. A geometrically curve US transducer array that is small enough to wrap around the vagus nerve was fabricated. An experiment was conducted in water, with 48 US elements curved in a 1 mm radius and excited at 15 MHz to test the focusing capabilities of the device. The results show that the geometrical curvature focused the US to an area with a width and height of 110 μm and 550 μm. This will be equivalent to only 2.1% of the cross section of the vagus nerve, showing the potential of focused US to stimulate individual neuronal fibers within the vagus nerve selectively.

    document

  12. Embedding Small Electronic Components into Tiny Flexible Implants
    Anna Pak; Wouter A. Serdijn; Vasiliki Giagka;
    In Book of Abstracts, 2019 International Winterschool on Bioelectronics Conference (BioEl 2019),
    Kirchberg, Tirol, Austria, 16-23 March 2019.
    document

  13. Towards a Semi-Flexible Parylene-Based Platform Technology for Active Implantable Medical Devices
    Nasim Bakhshaee Babaroud; Marta Kluba; Ronald Dekker; Wouter Serdijn; Vasiliki Giagka;
    In Book of Abstracts, 2019 International Winterschool on Bioelectronics Conference (BioEl 2019),
    Kirchberg, Tirol, Austria, 16-23 March 2019.
    document

  14. An Ultra High-Frequency 8-Channel Neurostimulator Circuit with 68% Peak Power Efficiency
    Alessandro Urso; Vasiliki Giagka; Marijn Van Dongen; Wouter A. Serdijn;
    In Book of Abstracts, 2019 International Symposium on Integrated Circuits and Systems (ISICAS 2019),
    Venice, Italy, IEEE, 29-30 August 2019. DOI: 10.1109/TBCAS.2019.2920294
    document

  15. Monolithic Integration of an In-situ Smart Sensor in a Silicon-based Organ-on-a-chip Platform for Monitoring the Temperature of Stem Cell Culture
    R. Ponte; V. Giagka; W. Serdijn;
    In Book of Abstracts, SAFE 2019,
    Delft, the Netherlands, July 4-5 2019.
    document

  16. Towards a semi-flexible parylene-based platform technology for active implantable medical devices
    N. Bakhshaee Babaroud; M. Kluba; R. Dekker; W. Serdijn; V. Giagka;
    In Book of Abstracts, SAFE 2019,
    Delft, the Netherlands, July 4-5 2019.
    document

  17. Polymer-Encapsulated Single-Chip Implants for Bioelectronic Medicine
    K. Nanbakhsh; W. Serdijn; V. Giagka;
    In Book of Abstracts, SAFE 2019,
    Delft, the Netherlands, July 4-5 2019.
    document

  18. Flexible, graphene-based active implant for spinal cord stimulation in rodents
    A.I. Velea; S. Vollebregt; V. Giagka;
    In Book of Abstracts, SAFE 2019,
    Delft, the Netherlands, July 4-5 2019.
    document

  19. Design and MEMS microfabrication of a multifunctional smart optrode for combined optogenetics and electrophysiology studies
    R. Ponte; C. Huang; V. Giagka; W. Serdijn;
    In Book of Abstracts, SAFE 2019,
    Delft, the Netherlands, July 4-5 2019.
    document

  20. Effect of Signals on the Encapsulation Performance of Parylene Coated Platinum Tracks for Active Medical Implants
    Kambiz Nanbakhsh; Marta Kluba; B. Pahl; F. Bourgeois; Ronald Dekker; Wouter Serdijn; V. Giagka;
    In Proc. 41st Int. Conf. of the IEEE Engineering in Medicine and Biology (EMBC) 2019,
    Berlin, Germany, IEEE, July 23-27 2019.
    document

  21. Embedding small and thin electronics into flexible implants
    A. Pak; W.A. Serdijn; V. Giagka;
    In Book of Abstracts, SAFE 2019,
    Delft, the Netherlands, July 4-5 2019.
    document

  22. A Chip Integrity Monitor for Evaluating Long-term Encapsulation Performance Within Active Flexible Implants
    Omer Can Akgun; Kambiz Nanbakhsh; Vasiliki Giagka; Wouter A. Serdijn;
    In Proc. IEEE Biomedical Circuits and Systems Conference (BioCAS 2019),
    IEEE, October 17-19 2019.
    document

  23. Towards a Microfabricated Flexible Graphene-Based Active Implant for Tissue Monitoring During Optogenetic Spinal Cord Stimulation
    A.I. Velea; S. Vollebregt; V. Giagka;
    In Book of Abstracts, IEEE Nanotech. Mater. Dev. Conf. (NMDC) 2019,
    Stockholm, Sweden, IEEE, Oct. 2019.
    Abstract: ... Our aim is to develop a smart neural interface with transparent electrodes to allow for electrical monitoring of the site of interest during optogenetic stimulation of the spinal cord. In this work, we present the microfabrication process for the wafer-level development of such a compact, active, transparent and flexible implant. The transparent, passive array of electrodes and tracks have been developed using graphene, on top of which chips have been bonded using flip-chip bonding techniques. To provide high flexibility, soft encapsulation, using polydimethylsiloxane (PDMS) has been used. Preliminary measurements after the bonding process have shown resistance values in the range of kΩ for the combined tracks and ball-bonds.

    document

  24. Towards a Microfabricated Flexible Graphene-Based Active Implant for Tissue Monitoring During Optogenetic Spinal Cord Stimulation
    A.I. Velea; S. Vollebregt; T. Hosman; A. Pak; V. Giagka;
    In Proceedings IEEE Nanotechnology Materials and Devices Conference (NMDC) 2019,
    Stockholm, Sweden, Oct. 2019.
    Abstract: ... This work aims to develop a smart neural interface with transparent electrodes to allow for electrical monitoring of the site of interest during optogenetic stimulation of the spinal cord. In this paper, a microfabrication process for the wafer-level development of such a compact, active, transparent and flexible implant is presented. Graphene has been employed to form the transparent array of electrodes and tracks, on top of which chips have been bonded using flip-chip bonding techniques. To provide high flexibility, soft encapsulation, using polydimethylsiloxane (PDMS) has been used. Making use of the "Flex-to-Rigid" (F2R) technique, cm-size graphene-on-PDMS structures have been suspended and characterized using Raman spectroscopy to qualitatively evaluate the graphene layer, together with 2-point measurements to ensure the conductivity of the structure. In parallel, flip-chip bonding processes of chips on graphene structures were employed and the 2-point electrical measurement results have shown resistance values in the range of kΩ for the combined tracks and ball-bonds.

    document

  25. Realizing flexible bioelectronic medicines for accessing the peripheral nerves – technology considerations
    Vasiliki Giagka; Wouter Serdijn;
    Bioelectronic Medicine,
    Volume 4, Issue 8, June 26 2018. DOI: 10.1186/s42234-018-0010-y
    document

  26. An Energy-Efficient, Inexpensive, Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats
    Olafsdottir, Gudrun Erla; Serdijn, Wouter A.; Giagka, Vasiliki;
    In Proc. 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society,
    Honolulu, HI, USA, IEEE, July 17-21 2018.
    document

  27. An Ultrasonically Powered and Controlled Ultra-High-Frequency Biphasic Electrical Neurostimulator
    Lucia Tacchetti; Wouter A. Serdijn; Vasiliki Giagka;
    In proc. IEEE Biomedical Circuits and Systems Conference (BioCAS 2018),
    IEEE, Oct. 17-19 2018.
    document

  28. Design and Custom Fabrication of a Smart Temperature Sensor for an Organ-on-a-chip Platform
    Martins da Ponte, Ronaldo; Vasiliki Giagka; Wouter A. Serdijn;
    In proc. IEEE Biomedical Circuits and Systems Conference (BioCAS 2018),
    IEEE, Oct. 17-19 2018.
    document

  29. MEMS-Electronics Integration: A Smart Temperature Sensor for an Organ-on-a-chip Platform
    Martins da Ponte, Ronaldo; Vasiliki Giagka; Wouter A. Serdijn;
    In Proc. ProRISC,
    Enschede, the Netherlands, June 7-8 2018.
    document

  30. Circuit and systems for polymeric implants: designing towards increased device lifetimes
    K. Nanbakhsh; V. Giagka; W.A. Serdijn;
    In Proc. ProRISC,
    Enschede, the Netherlands, June 7-8 2018.
    document

  31. Towards a Family of Customisable Flexible Neural Implants
    Vasiliki Giagka; Wouter Serdijn;
    In Book of Abstracts, 6th Dutch Bio-Medical Engineering Conference, 26 and 27 January 2017, Egmond aan Zee, The Netherlands,
    2017.
    document

  32. A wireless sensor for monitoring encapsulation performance in non-hermetic implants
    K. Nanbakhsh; V. Giagka; W. A. Serdijn;
    In Proc. Design of Medical Devices Conf. (DMD) 2017 Microfabrication for Medical Devices,
    Eindhoven, 14 – 15 Nov. 2017.
    document

  33. Towards a Flexible Implant with Distributed Electronics, Wireless Communication and Energy Transfer
    Martins da Ponte, Ronaldo; Vasiliki Giagka; Wouter Serdijn;
    In Book of Abstracts, 6th Dutch Bio-Medical Engineering Conference, 26 and 27 January 2017, Egmond aan Zee, The Netherlands,
    2017.
    document

  34. MEMS-electronics integration: a smart temperature sensor for an organ-on-a-chip platform
    Martins da Ponte, Ronaldo; V. Giagka; W.A. Serdijn;
    In Proc. Design of Medical Devices Conf. (DMD) 2017 Microfabrication for Medical Devices,
    Eindhoven, 14 – 15 Nov 2017.
    document

  35. Towards a wearable near infrared spectroscopic probe for monitoring concentrations of multiple chromophores in biological tissue in vivo
    Danial Chitnis; Dimitrios Airantzis; David Highton; Rhys Williams; Phong Phan; Vasiliki Giagka; Samuel Powell; Robert J Cooper; Ilias Tachtsidis; Martin Smith; Clare E Elwell; Jeremy C Hebden; Nicholas Everdell;
    Review of Scientific Instruments,
    Volume 87, Issue 6, pp. 065112, June 1 2016. Publisher: AIP Publishing.
    document

  36. Flexible active electrode arrays with ASICs that fit inside the rat's spinal canal
    Vasiliki Giagka; Andreas Demosthenous; Nick Donaldson;
    Biomedical Microdevices,
    Volume 17, Issue 6, pp. 106 - 118, December 2015. DOI 10.1007/s10544-015-0011-5.
    document

  37. An Implantable Versatile Electrode-Driving ASIC for Chronic Epidural Stimulation in Rats
    Vasiliki Giagka; Clemens Eder; Nick Donaldson; Andreas Demosthenous;
    IEEE Transactions on Biomedical Circuits and Systems,
    Volume 9, Issue 3, pp. 387 - 400, June 2015. DOI 10.1109/TBCAS.2014.2330859.
    document

  38. Flexible Active Electrode Arrays For Epidural Spinal Cord Stimulation
    Vasiliki Giagka;
    PhD thesis, University College London, Analogue and Biomedical Electronics Group, Department of Electronic and Electrical Engineering, January, 28 2015.
    document

  39. Evaluation and optimization of the mechanical strength of bonds between metal foil and aluminium pads on thin ASICs using gold ball studs as micro-rivets
    Vasiliki Giagka; Anne Vanhoestenberghe; Nick Donaldson; Andreas Demosthenous;
    In Proc. Electronics System-Integration Technology Conference,
    Helsinki, Finland, IEEE, pp. 1 - 5, September 2014.
    document

  40. Controlled silicon IC thinning on individual die level for active implant integration using a purely mechanical process
    Vasiliki Giagka; Nooshin Saeidi; Andreas Demosthenous; Nick Donaldson;
    In Proc. 64th Electronic Components and Technology Conference,
    Orlando, Florida, USA, IEEE, pp. 2213 - 2219, May 2014.
    document

  41. A dedicated electrode driving ASIC for epidural spinal cord stimulation in rats
    Vasiliki Giagka; Clemens Eder; Virgilio Valente; Anne Vanhoestenberghe; Nick Donaldson; Andreas Demosthenous;
    In Proc. 20th International Conference on Electronics, Circuits and Systems,
    Abu Dhabi, UAE, IEEE, pp. 469 - 472, December 2013.
    document

  42. In vivo evaluation and failure analysis of an implantable electrode array for epidural spinal cord stimulation in paralysed rats
    Vasiliki Giagka; Anne Vanhoestenberghe; Nick Donaldson; Andreas Demosthenous;
    In imaps-uk Annual Conference MicroTech 2013 Showcasing Microassembly,
    Cambridge, UK, pp. 1, March 2013.

  43. An Implantable Stimulator System For Neuro-Rehabilitation In Paralyzed Rats
    Vasiliki Giagka; Nick Donaldson; Andreas Demosthenous;
    In Young Researchers Futures Meeting - Neural Engineering,
    Warwick, UK, pp. 1, September 2012.

  44. Towards a low-power active epidural spinal cord array controlled through a two wire interface
    Vasiliki Giagka; Andreas Demosthenous; Nick Donaldson;
    In Proc. 8th Conf. Ph.D. Research in Microelectronics and Electronics,
    Aachen, Germany, VDE, pp. 247 - 250, June 2012.
    document

  45. Flexible platinum electrode arrays for epidural spinal cord stimulation in paralyzed rats: An in vivo and in vitro evaluation
    Vasiliki Giagka; Anne Vanhoestenberghe; Nikolaus Wenger; Pavel Musienko; Nick Donaldson; Andreas Demosthenous;
    In Proc. 3rd Annual Conf. International Functional Electrical Stimulation Society UK and Ireland Chapter,
    Birmingham, UK, pp. 52 - 53, April 2012.
    document

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