A microarray is a multiplex lab-on-a-chip. Its purpose is to simultaneously detect the expression of thousands of biological interactions. It is a two-dimensional array on a solid substrate—usually a glass slide or silicon thin-film cell—that assays (tests) large amounts of biological material using high-throughput screening miniaturized, multiplexed and parallel processing and detection methods. The concept and methodology of microarrays was first introduced and illustrated in antibody microarrays by Tse Wen Chang in 1983 in a scientific publication and a series of patents. The "gene chip" industry started to grow significantly after the 1995 Science Magazine article by the Ron Davis and Pat Brown labs at Stanford University. With the establishment of companies, such as Affymetrix, Agilent, Applied Microarrays, Arrayjet, Illumina, and others, the technology of DNA microarrays has become the most sophisticated and the most widely used, while the use of protein, peptide and carbohydrate microarrays is expanding.
A sensor is a device that produces an output signal for the purpose of detecting a physical phenomenon.
A biosensor is an analytical device, used for the detection of a chemical substance, that combines a biological component with a physicochemical detector. The sensitive biological element, e.g. tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids, etc., is a biologically derived material or biomimetic component that interacts with, binds with, or recognizes the analyte under study. The biologically sensitive elements can also be created by biological engineering. The transducer or the detector element, which transforms one signal into another one, works in a physicochemical way: optical, piezoelectric, electrochemical, electrochemiluminescence etc., resulting from the interaction of the analyte with the biological element, to easily measure and quantify. The biosensor reader device connects with the associated electronics or signal processors that are primarily responsible for the display of the results in a user-friendly way. This sometimes accounts for the most expensive part of the sensor device, however it is possible to generate a user friendly display that includes transducer and sensitive element. The readers are usually custom-designed and manufactured to suit the different working principles of biosensors.
Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There are a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by various performance metrics, such as spectral response. Semiconductor-based photodetectors typically use a p–n junction that converts photons into charge. The absorbed photons make electron–hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. Solar cells convert some of the light energy absorbed into electrical energy.
Neural engineering is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, or enhance neural systems. Neural engineers are uniquely qualified to solve design problems at the interface of living neural tissue and non-living constructs.
An active-pixel sensor (APS) is an image sensor, which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a photodetector and one or more active transistors. In a metal–oxide–semiconductor (MOS) active-pixel sensor, MOS field-effect transistors (MOSFETs) are used as amplifiers. There are different types of APS, including the early NMOS APS and the now much more common complementary MOS (CMOS) APS, also known as the CMOS sensor. CMOS sensors are used in digital camera technologies such as cell phone cameras, web cameras, most modern digital pocket cameras, most digital single-lens reflex cameras (DSLRs), mirrorless interchangeable-lens cameras (MILCs), and lensless imaging for cells.
Nanoelectronics refers to the use of nanotechnology in electronic components. The term covers a diverse set of devices and materials, with the common characteristic that they are so small that inter-atomic interactions and quantum mechanical properties need to be studied extensively. Some of these candidates include: hybrid molecular/semiconductor electronics, one-dimensional nanotubes/nanowires or advanced molecular electronics.
Joseph Wang is an American biomedical engineer and inventor. He is a Distinguished Professor, SAIC Endowed Chair, and former Chair of the Department of Nanoengineering at the University of California, San Diego, who specialized in nanomachines, biosensors, nano-bioelectronics, wearable devices, and electrochemistry. He is also the Director of the UCSD Center of Wearable Sensors and co-director of the UCSD Center of Mobile Health Systems and Applications (CMSA).
Bioelectronics is a field of research in the convergence of biology and electronics.
Microelectrode arrays (MEAs) are devices that contain multiple microelectrodes through which neural signals are obtained or delivered, essentially serving as neural interfaces that connect neurons to electronic circuitry. There are two general classes of MEAs: implantable MEAs, used in vivo, and non-implantable MEAs, used in vitro.
Magnetomyography (MMG) is a technique for mapping muscle activity by recording magnetic fields produced by electrical currents occurring naturally in the muscles, using arrays of SQUIDs. It has a better capability than electromyography for detecting slow or direct currents. The magnitude of the MMG signal is in the scale of pico (10−12) to femto (10−15) Tesla (T). Miniaturizing MMG offers a prospect to modernize the bulky SQUID to wearable miniaturized magnetic sensors.
Mark G. Allen is a professor specializing in microfabrication, nanotechnology, and microelectromechanical systems at the University of Pennsylvania, where he is currently Alfred Fitler Moore Professor of Electrical and Systems Engineering Director of the Singh Center for Nanotechnology, and leader of the Microsensor and Microactuator Research Group. Prior to his joining the University of Pennsylvania in 2013, he was with the Georgia Institute of Technology, where he was Regents' Professor of Electrical and Computer Engineering and the J.M. Pettit Professor in Microelectronics. While at Georgia Tech, he also held multiple administrative positions, including Senior Vice Provost for Research and Innovation; Acting Director of the Georgia Electronic Design Center; and Inaugural Executive Director of Georgia Tech's Institute for Electronics and Nanotechnology. He was editor in chief of the Journal of Micromechanics and Microengineering (JMM), and currently serves on the editorial board of JMM as well as the journal Microsystems and Nanoengineering.
The organic electrochemical transistor (OECT) is an organic electronic device which functions like a transistor. The current flowing through the device is controlled by the exchange of ions between an electrolyte and the OECT channel composed of an organic conductor or semiconductor. The exchange of ions is driven by a voltage applied to the gate electrode which is in ionic contact with the channel through the electrolyte. The migration of ions between the channel and the electrolyte is accompanied by electrochemical redox reactions occurring in the channel material. The electrochemical redox of the channel along with ion migration changes the conductivity of the channel in a process called electrochemical doping. OECTs are being explored for applications in biosensors, bioelectronics and large-area, low-cost electronics. OECTs can also be used as multi-bit memory devices that mimic the synaptic functionalities of the brain. For this reason, OECTs can be also being investigated as elements in neuromorphic computing applications.
Stéphanie P. Lacour is a French neurotechnologist and full professor holding the Foundation Bertarelli Chair in Neuroprosthetic Technology at the Swiss Federal Institute of Technology in Lausanne (EPFL). Lacour is a pioneer in the field of stretchable electronics and directs a laboratory at EPFL which specializes in the development of Soft BioElectronic Interfaces to enable seamless integration of neuroprosthetic devices into human tissues. Lacour is also a co-founding member and director of the Center for Neuroprosthetics at the EPFL Satellite Campus in Geneva, Switzerland.
Carlotta Guiducci is an Italian bio-engineer. Her research is invested in bio-molecular analysis based on lab-on-a-chip devices. She is an Associate Professor at EPFL and head of the Laboratory of Life Sciences Electronics located at EPFL's Lausanne campus.
Edoardo Charbon is a Swiss electrical engineer. He is a professor of quantum engineering at EPFL and the head of the Laboratory of Advanced Quantum Architecture (AQUA) at the School of Engineering.
Wei Gao is a Chinese-American biomedical engineer who currently serves as a professor of medical engineering at the California Institute of Technology (Caltech). Gao has been a professor at Caltech since 2017 and is an associate editor of the journals Science Advances, Biosensors and Bioelectronics, npj Flexible Electronics (Nature), Journal on Flexible Electronics (IEEE), and Sensors & Diagnosis.
Willy Sansen was an electrical engineer, academic, and author. He is an emeritus professor of sngineering science at the Katholieke Universiteit Leuven.
Stretchable microelectrode arrays (stretchable MEAs or sMEAs) (also referred to as stretchable multielectrode arrays) are a specialized type of microelectrode array (MEA) with a key advantage; they can be deformed, stretched, bent, and twisted while maintaining electrical functionality whereas standard MEAs break upon mechanical loading. Flexible MEAs (flexMEA), which are often confounded with stretchable MEAs, lie in between stretchable MEAs and standard MEA in terms of their mechanical properties because they bend and twist to some degree, but not stretch. Just like traditional MEAs, stretchable MEAs consist of a few thousand microelectrodes that allow recording or stimulation of electrical signals from cells (neurons, muscles, etc.), and are used in vivo in a living being or in vitro with cell cultures.
