A Novel Low-Cost Method for Fabrication of 2D Multi-Electrode Array (MEA) to Evaluate Functionality of Neuronal Cells

In this paper, a fabrication method for two-dimensional multi-electrode arrays (MEAs) using inexpensive material and method is proposed. The focus in this work is on the design and fabrication of 2D Microelectrode arrays using metallic electrodes on a silica substrate. Titanium/gold multi-electrode arrays containing 60 electrodes with optimized metal thicknesses and 30 μm diameter, covered with thin modified SU-8 insulator layer as biocompatible material have been designed and manufactured using the standard photolithography-based microfabrication method. The utilization of affordable and more accessible materials and simpler techniques can be mentioned as the distinct point of the proposed fabrication method. Using these multi-electrode arrays, it is possible to either record or stimulate cells by accessing multiple sites of cell tissues and collect signals from the sources around each electrode simultaneously. Precisely adjusting the size, distance, and number of microelectrodes causes high measurement selectivity and reliability which has been taken into account in the design of the microelectrodes. In this study, we manufactured a preliminary representative MEA and the bio-compatibility of the manufactured MEA is going to be evaluated by neural cells, obtained from rat cortices. The main aim of this study is to compare our inexpensive strategy with other approaches.

Download Full-text

Low-cost and easy-fabrication lightweight drivable electrode array for multiple-regions electrophysiological recording in free-moving mice

Journal of Neural Engineering ◽

10.1088/1741-2552/ac494e ◽

2022 ◽

Author(s):

Chongyang Sun ◽

Yi Cao ◽

Jianyu Huang ◽

Kang Huang ◽

Yi Lu ◽

...

Keyword(s):

Neural Circuit ◽

Low Cost ◽

Electrode Array ◽

Ethylene Vinyl Acetate ◽

Lateral Septum ◽

Electrophysiological Recording ◽

Electrode Arrays ◽

Electrophysiological Recordings ◽

Seeking Behavior ◽

Multiple Regions

Abstract Objective. Extracellular electrophysiology has been widely applied to neural circuit dissections. However, long-term multiregional recording in free-moving mice remains a challenge. Low-cost and easy-fabrication of elaborate drivable electrodes is required for their prevalence. Approach. A three-layer nested construct (OD ~1.80 mm, length ~10 mm, <0.1g) was recruited as a drivable component, which consisted of an ethylene-vinyl acetate copolymer (EVA) heat-shrinkable tube, non-closed loop ceramic bushing, and stainless ferrule with a bulge twining silver wire. The supporting and working components were equipped with drivable components to be assembled into a drivable microwire electrode array with a nested structure (drivable MEANS). Two drivable microwire electrode arrays were independently implanted for chronic recording in different brain areas at respective angles. An optic fiber was easily loaded into the drivable MEANS to achieve optogenetic modulation and electrophysiological recording simultaneously. Main results. The drivable MEANS had lightweight (~ 0.37 g), small (~ 15 mm ×15 mm × 4 mm), and low cost (≤ $64.62). Two drivable MEANS were simultaneously implanted in mice, and high-quality electrophysiological recordings could be applied ≥ 5 months after implantation in freely behaving animals. Electrophysiological recordings and analysis of the lateral septum (LS) and lateral hypothalamus (LH) in food-seeking behavior demonstrated that our drivable MEANS can be used to dissect the function of neural circuits. An optical fiber-integrated drivable MEANS (~ 0.47 g) was used to stimulate and record LS neurons, which suggested that changes in working components can achieve more functions than electrophysiological recordings, such as optical stimulation, drug release, and calcium imaging. Significance. Drivable MEANS is an easily fabricated, lightweight drivable microwire electrode array for multiple-region electrophysiological recording in free-moving mice. Our design is likely to be a valuable platform for both current and prospective users, as well as for developers of multifunctional electrodes for free-moving mice.

Download Full-text

A Novel, Low Cost and Versatile Fabrication Method of Flexible Multi-electrode Array for Spinal Cord Stimulation

2020 27th National and 5th International Iranian Conference on Biomedical Engineering (ICBME) ◽

10.1109/icbme51989.2020.9319449 ◽

2020 ◽

Author(s):

Faezeh Shanehsazzadeh ◽

Shahin Rouhi ◽

Tala Ahmadvand ◽

Mahrokh Namazi ◽

Sahar Kiani ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Stimulation ◽

Low Cost ◽

Electrode Array ◽

Fabrication Method ◽

Multi Electrode Array

Download Full-text

All-Solid-State Potentiometric Ion-Sensors Based on Tailored Imprinted Polymers for Pholcodine Determination

Polymers ◽

10.3390/polym13081192 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1192

Author(s):

Hisham S. M. Abd-Rabboh ◽

Abd El-Galil E. Amr ◽

Abdulrahman A. Almehizia ◽

Ayman H. Kamel

Keyword(s):

Solid State ◽

Low Cost ◽

Cost Effective ◽

Pharmaceutical Formulations ◽

Measurement Sensitivity ◽

Serum Samples ◽

Multiwalled Carbon ◽

Imprinted Polymers ◽

High Measurement ◽

Liquid Chromatographic

In recent times, the application of the use of ion-selective electrodes has expanded in the field of pharmaceutical analyses due to their distinction from other sensors in their high selectivity and low cost of measurement, in addition to their high measurement sensitivity. Cost-effective, reliable, and robust all-solid-state potentiometric selective electrodes were designed, characterized, and successfully used for pholcodine determination. The design of the sensor device was based on the use of a screen-printed electrode modified with multiwalled carbon nanotubes (MWCNTs) as a solid-contact transducer. Tailored pholcodine (PHO) molecularly imprinted polymers (MIPs) were prepared, characterized, and used as sensory receptors in the presented potentiometric sensing devices. The sensors exhibited a sensitivity of 31.6 ± 0.5 mV/decade (n = 5, R2 = 0.9980) over the linear range of 5.5 × 10−6 M with a detection limit of 2.5 × 10−7 M. Real serum samples in addition to pharmaceutical formulations containing PHO were analyzed, and the results were compared with those obtained by the conventional standard liquid chromatographic approach. The presented analytical device showed an outstanding efficiency for fast, direct, and low-cost assessment of pholcodine levels in different matrices.

Download Full-text

The Importance of Intraoperative Plain Radiographs during Cochlear Implant Surgery in Patients with Normal Anatomy

Applied Sciences ◽

10.3390/app11094144 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4144

Author(s):

Ohad Cohen ◽

Jean-Yves Sichel ◽

Chanan Shaul ◽

Itay Chen ◽

J. Thomas Roland ◽

...

Keyword(s):

Cochlear Implant ◽

Electrode Array ◽

Cost Effective ◽

X Rays ◽

Normal Anatomy ◽

Electrode Arrays ◽

Plain Radiographs ◽

Hearing Function ◽

Tertiary Center ◽

Cochlear Implant Surgery

Although malpositioning of the cochlear implant (CI) electrode array is rare in patients with normal anatomy, when occurring it may result in reduced hearing outcome. In addition to intraoperative electrophysiologic tests, imaging is an important modality to assess correct electrode array placement. The purpose of this report was to assess the incidence and describe cases in which intraoperative plain radiographs detected a malpositioned array. Intraoperative anti-Stenver’s view plain X-rays are conducted routinely in all CI surgeries in our tertiary center before awakening the patient and breaking the sterile field. Data of patients undergoing 399 CI surgeries were retrospectively analyzed. A total of 355 had normal inner ear and temporal bone anatomy. Patients with intra or extracochlear malpositioned electrode arrays demonstrated in the intraoperative X-ray were described. There were four cases of electrode array malposition out of 355 implantations with normal anatomy (1.1%): two tip fold-overs, one extracochlear placement and one partial insertion. All electrodes were reinserted immediately; repeated radiographs were normal and the patients achieved good hearing function. Intraoperative plain anti-Stenver’s view X-rays are valuable to confirm electrode array location, allowing correction before the conclusion of surgery. These radiographs are cheaper, faster, and emit much less radiation than other imaging options, making them a viable cost-effective tool in patients with normal anatomy.

Download Full-text

Precise Alignment of Micromachined Electrode Arrays With V1 Functional Maps

Journal of Neurophysiology ◽

10.1152/jn.00120.2007 ◽

2007 ◽

Vol 97 (5) ◽

pp. 3781-3789 ◽

Cited By ~ 12

Author(s):

Ian Nauhaus ◽

Dario L. Ringach

Keyword(s):

Receptive Field ◽

Electrode Array ◽

Theoretical Models ◽

Orientation Tuning ◽

Feedback Signal ◽

Electrode Arrays ◽

Tuning Curves ◽

Alignment Procedure ◽

Receptive Field Properties ◽

Orientation Maps

Recent theoretical models of primary visual cortex predict a relationship between receptive field properties and the location of the neuron within the orientation maps. Testing these predictions requires the development of new methods that allow the recording of single units at various locations across the orientation map. Here we present a novel technique for the precise alignment of functional maps and array recordings. Our strategy consists of first measuring the orientation maps in V1 using intrinsic optical imaging. A micromachined electrode array is subsequently implanted in the same patch of cortex for electrophysiological recordings, including the measurement of orientation tuning curves. The location of the array within the map is obtained by finding the position that maximizes the agreement between the preferred orientations measured electrically and optically. Experimental results of the alignment procedure from two implementations in monkey V1 are presented. The estimated accuracy of the procedure is evaluated using computer simulations. The methodology should prove useful in studying how signals from the local neighborhood of a neuron, thought to provide a dominant feedback signal, shape the receptive field properties in V1.

Download Full-text

An ultra-low-cost electroporator with microneedle electrodes (ePatch) for SARS-CoV-2 vaccination

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2110817118 ◽

2021 ◽

Vol 118 (45) ◽

pp. e2110817118

Author(s):

Dengning Xia ◽

Rui Jin ◽

Gaurav Byagathvalli ◽

Huan Yu ◽

Ling Ye ◽

...

Keyword(s):

Immune Responses ◽

Large Scale ◽

Low Cost ◽

Electrode Array ◽

Dna Vaccination ◽

Intradermal Injection ◽

Antibody Responses ◽

Transient Effects ◽

Electric Pulses ◽

High Electric Field Strength

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens with pandemic potential requires safe, protective, inexpensive, and easily accessible vaccines that can be developed and manufactured rapidly at a large scale. DNA vaccines can achieve these criteria, but induction of strong immune responses has often required bulky, expensive electroporation devices. Here, we report an ultra-low-cost (<1 USD), handheld (<50 g) electroporation system utilizing a microneedle electrode array (“ePatch”) for DNA vaccination against SARS-CoV-2. The low cost and small size are achieved by combining a thumb-operated piezoelectric pulser derived from a common household stove lighter that emits microsecond, bipolar, oscillatory electric pulses and a microneedle electrode array that targets delivery of high electric field strength pulses to the skin’s epidermis. Antibody responses against SARS-CoV-2 induced by this electroporation system in mice were strong and enabled at least 10-fold dose sparing compared to conventional intramuscular or intradermal injection of the DNA vaccine. Vaccination was well tolerated with mild, transient effects on the skin. This ePatch system is easily portable, without any battery or other power source supply, offering an attractive, inexpensive approach for rapid and accessible DNA vaccination to combat COVID-19, as well as other epidemics.

Download Full-text

Design and development of a multichannel potentiometer for monitoring an electrode array and its application in flow analysis

Journal of Automated Methods and Management in Chemistry ◽

10.1155/s1463924602000147 ◽

2002 ◽

Vol 24 (4) ◽

pp. 105-110 ◽

Cited By ~ 2

Author(s):

Jarbas J. R. Rohwedder ◽

Celio Pasquini ◽

Ivo M. Raimundo, Jr. ◽

M. Conceiçao ◽

B. S. M. Montenegro ◽

...

Keyword(s):

Standard Deviation ◽

Flow Analysis ◽

Reference Electrode ◽

Electrode Array ◽

Ion Selective Electrodes ◽

Electrode Arrays ◽

Figures Of Merit ◽

Flow Through ◽

The Individual ◽

Intense Signal

A versatile potentiometer that works with electrode arrays in flow injection and/or monosegmented flow systems is described. The potentiometer is controlled by a microcomputer that allows individual, sequential multiplexed or random accesses to eight electrodes while employing only one reference electrode. The instrument was demonstrated by monitoring an array of seven flow-through ion-selective electrodes for Ag+and for three electrodes for Cl-, Ca2+and K+. The figures of merit of the individual and multiplexed (summed) readings of the electrode array were compared. The absolute standard deviation of the measurements made by summing the potential of two or more electrodes was maintained constant, thus improving the precision of the measurements. This result shows that an attempt to combine the signals of the electrodes to produce a more intense signal in the Hadamard strategy is feasible and accompanied by a proportional improvement in the precision of individual measurements. The preliminary tests suggest that the system can allow for 270 determinations per hour, with a linear range from1.0×10−2to1.0×10−4mol l-1for the three di¡erent analytes. Detection limits were estimated as3.1×10−5,3.0×10−6and1.0×10−5mol l-1for Cl-, Ca2+and K+, respectively.

Download Full-text

LTCC Based Multi-Electrode Arrays for In-Vitro Cell Culture

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-tha12 ◽

2015 ◽

Vol 2015 (CICMT) ◽

pp. 000269-000274

Author(s):

Heike Bartsch ◽

Dirk Stöpel ◽

Marcel Himmerlich ◽

Martin Baca ◽

Philipp Stadie ◽

...

Keyword(s):

Cell Culture ◽

Laser Scanning ◽

Neuronal Cell ◽

Laser Scanning Microscopy ◽

Gold Electrodes ◽

Neural Cells ◽

Electrode Arrays ◽

Green Tape ◽

High Level

Neurobiological concepts based on state-of-the art technology have so far lacked the complexity of actual high-level neurobiological systems. Two key advances are needed to improve our understanding of such systems: in vitro 3D-neuronal cell culture and 3D MEA systems for measuring such 3D-cultures. These requirements call for smart multilayer and packaging technology. The material Green Tape TM from DuPont Nemours is chosen for the presented works, because its compatibility and those of available metallisation with cell cultures is already proven. An LTCC multilayer circuit with gold electrodes is the base of the 3D MEA. The layout of the 3D MEA is designed to fit the MEA2100-System for in vitro recording from Multi Channel Systems and enable thus a comparable data processing to established 2D MEAs Slots. The surface topography of the thick film electrodes and the surface state is investigated with laser scanning microscopy, SEM, XPS and measurements of the wetting angle of contact. The impedance of the screen printed electrodes is discussed taking these data into account. Their impedance amounts to 24 kΩ and are falls thus below the impedance of commercially available electroplated gold electrodes of 30 kΩ. First promising results have been achieved using 3D MEAs for 2D culture of human pluripotent stem cell derived neural cells.

Download Full-text