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Martins Da Ponte, R. (author), Gaio, N. (author), van Zeijl, H.W. (author), Vollebregt, S. (author), Dijkstra, Paul (author), Dekker, R. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)One of the many applications of organ-on-a-chip (OOC) technology is the study of biological processes in human induced pluripotent stem cells (iPSCs) during pharmacological drug screening. It is of paramount importance to construct OOCs equipped with highly compact in situ sensors that can accurately monitor, in real time, the extracellular...journal article 2021
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Lamont, C. (author), Grego, T. (author), Nanbakhsh, K. (author), Idil, A. Shah (author), Giagka, Vasiliki (author), Vanhoestenberghe, A. (author), Cogan, S. (author), Donaldson, N. (author)Objective. Ensuring the longevity of implantable devices is critical for their clinical usefulness. This is commonly achieved by hermetically sealing the sensitive electronics in a water impermeable housing, however, this method limits miniaturisation. Alternatively, silicone encapsulation has demonstrated long-term protection of implanted thick...journal article 2021
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Lamont, C. (author), Grego, T. (author), Nanbakhsh, K. (author), Idil, A. Shah (author), Giagka, Vasiliki (author), Vanhoestenberghe, A. (author), Cogan, S. (author), Donaldson, N. (author)Objective. Ensuring the longevity of implantable devices is critical for their clinical usefulness. This is commonly achieved by hermetically sealing the sensitive electronics in a water impermeable housing, however, this method limits miniaturisation. Alternatively, silicone encapsulation has demonstrated long-term protection of implanted...journal article 2021
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Kawasaki, S. (author), Dijkema, E. (author), Saccher, M. (author), Giagka, Vasiliki (author), Schleipen, J.J.H.B. (author), Dekker, R. (author)In the bioelectronic medicine field, vagus nerve stimulation (VNS) is a promising technique that is expected to treat numerous inflammatory conditions, in addition to the currently FDA approved treatment for epilepsy, depression and obesity [1]. However, current VNS techniques are still limited in the spatial resolution that they can achieve,...conference paper 2021
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Kolovou Kouri, K. (author), Soloukey, Sadaf (author), Huygen, F.J.P.M. (author), Harhangi, Biswadjiet S. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)This paper presents the development of a Dorsal Root Ganglion (DRG) stimulator system intended for use in early clinical trials for motor recovery after Spinal Cord Injury (SCI). It allows for independent control of multisite/multilevel bilateral (on both sides of the spinal cord) stimulation, it can supply a high output current of 25.4mA,...conference paper 2021
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Velea, A. (author), Vollebregt, S. (author), Hosman, T.B. (author), Pak, A. (author), Giagka, Vasiliki (author)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...conference paper 2020
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Akgün, O.C. (author), Nanbakhsh, K. (author), Giagka, Vasiliki (author), Serdijn, W.A. (author)For mm-sized implants incorporating silicon integrated circuits, ensuring lifetime operation of the chip within the corrosive environment of the body still remains a critical challenge. For the chip's packaging, various polymeric and thin ceramic coatings have been reported, demonstrating high biocompatibility and barrier properties. Yet, for...journal article 2020
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Nanbakhsh, K. (author), Ritasalo, R. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)In this work, we investigate the insulating performance of an atomic layer deposited (ALD) HfO2 - polymer bilayer for platinum (Pt) metallization. As test vehicles, Pt interdigitated comb structures (IDC) were designed and fabricated on SiO2/Si substrates. The IDCs were first coated with a 100 nm thin HfO2 ALD layer. A group of samples was...conference paper 2020
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Velea, A. (author), Vollebregt, S. (author), Wardhana, G.K. (author), Giagka, Vasiliki (author)This paper reports on the characterization of a microfabricated wafer-scale, graphene-based, soft implant for spinal cord applications. Graphene is used because of its high transparency and good conductivity, making it suitable for optogenetic applications. Moreover it has a high mechanical strength and is potentially biocompatible. The implant...conference paper 2020
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Velea, A. (author), Vollebregt, S. (author), Giagka, Vasiliki (author)Patients affected by spinal cord injuries (SCI) are usually unable to perform trivial motor activities and thus, for therapeutic purposes, epidural spinal cord stimulation (ESCS) is currently used. Moreover, more exploratory research, using optogenetics, is being conducted in rodents for a better understanding of the mechanisms that occur while...poster 2020
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Bakhshaee Babaroud, N. (author), Dekker, R. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)Parylene-C has been used as a substrate and encapsulation material for many implantable medical devices. However, to ensure the flexibility required in some applications, minimize tissue reaction, and protect parylene from degradation in vivo an additional outmost layer of polydimethylsiloxane (PDMS) is desired. In such a scenario, the adhesion...conference paper 2020
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Giagka, Vasiliki (author)In a world where medicine is becoming more personalised the promise of Bioelectronic Medicine is that tiny implants will deliver energy in the form of electrical impulses, replacing pharmaceuticals, their conventional chemical counterparts. But how can we develop such tiny smart and autonomous implants that (need to) seamlessly interact with the...abstract 2020
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Bakhshaee Babaroud, N. (author), Dekker, R. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)Parylene-C has been used as a substrate and encapsulation material for many implantable medical devices. However, to ensure the flexibility required in some applications, minimize tissue reaction, and protect parylene from degradation in vivo an additional outmost layer of polydimethylsiloxane (PDMS) is desired. In such a scenario, the...conference paper 2020
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Guan, R. (author), Zufiria, Pedro G. (author), Giagka, Vasiliki (author), Serdijn, W.A. (author)This paper presents the main circuit design considerations for power-efficient and safe implantable electrical neurostimulators. Related to medical applications, low-frequency (LF) stimulation for generating new action potentials and kilohertz-frequency alternating current (KHFAC) for blocking unwanted neural activity are introduced,...conference paper 2020
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Akgün, O.C. (author), Nanbakhsh, K. (author), Giagka, Vasiliki (author), Serdijn, W.A. (author)One key obstacle in employing silicon integrated circuits in flexible implants is ensuring a long-term operation of the chip within the wet corrosive environment of the body. For this reason, throughout the years, various biocompatible insulating materials have been proposed, yet, evaluating their long-term encapsulation performance on...conference paper 2019
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Nanbakhsh, K. (author), Kluba, M.M. (author), Pahl, Barbara (author), Bourgeois, Florian (author), Dekker, R. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)Platinum is widely used as the electrode material for implantable devices. Owing to its high biostability and corrosion resistivity, platinum could also be used as the main metallization for tracks in active implants. Towards this goal, in this work we investigate the stability of parylene-coated Pt tracks using passive and active tests. The...conference paper 2019
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Wardhana, Gandhika K (author), Serdijn, W.A. (author), Vollebregt, S. (author), Giagka, Vasiliki (author), Vollebregt, Sten (author)Neural interface in the form of microelectrodes are used to monitor and treat spinal cord injury and other neurological disorders by the means of recording and stimulation. Despite of the apparent result of these electrical interventions, understanding of the mechanism behind neural stimulation is still inadequate. The use of optical monitoring...abstract 2019
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Bakhshaee Babaroud, N. (author), Kluba, M.M. (author), Dekker, R. (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)Active implantable medical devices have been developed for diagnosis, monitoring and treatment of large variety of neural disorders. Since the mechanical properties of these devices need to be matched to the tissue, soft materials, such as polymers are often preferred as a substrate [1]. Parylene is a good candidate, as it is highly...abstract 2019
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Malissovas, Anastasios (author), Serdijn, W.A. (author), Giagka, Vasiliki (author)As the era of Bioelectronic medicines (BEms) evolves, new technological challenges are generated, including miniaturized devices that are encapsulated with flexible materials and energized by wireless power transmission (WPT) techniques. Among them, magnetostatic, also known as inductive, and ultrasound (US) are the most viable candidates for...abstract 2019
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Martins Da Ponte, R. (author), Huang, C. (author), Giagka, Vasiliki (author), Serdijn, W.A. (author)Optogenetics is a neuromodulation method that holds great potential for the realization of advanced neuroprostheses due to its precise spatial-temporal control of neuronal activity [1]. The development of novel optogenetic implants (optrodes) may open new doors to investigate complex brain circuitry and chronical brain disorders, such as...abstract 2019