Testing microelectronic biofluidic systems

According to the 2005 International Technology Roadmap for Semiconductors, the integration of emerging nondigital CMOS technologies will require radically different test methods, posing a major challenge for designers and test engineers. One such technology is microelectronic fluidic (MEF) arrays, which have rapidly gained importance in many biological, pharmaceutical, and industrial applications. The advantages of these systems, such as operation speed, use of very small amounts of liquid, on-board droplet detection, signal conditioning, and vast digital signal processing, make them very promising. However, testable design of these devices in a mass-production environment is still in its infancy, hampering their low-cost introduction to the market. This article describes analog and digital MEF design and testing method

Prototype of calorimetric flow microsensor

An analytical model of calorimetric flow sensor has been developed. The results of the application of this model are utilized to develop a calorimetric flow microsensor with optimal functional characteristics. The technology to manufacture the microsensor is described. A prototype of the microsensor suitable to be used in the mass air flow meter has been designed. The basic characteristics of the microsensor are presented. © 2012 American Institute of Physics

Microfluidics and Nanofluidics: Science, Fabrication Technology (From Cleanrooms to 3D Printing) and Their Application to Chemical Analysis by Battery-Operated Microplasmas-On-Chips

The science and phenomena that become important when fluid-flow is confined in microfluidic channels are initially discussed. Then, technologies for channel fabrication (ranging from photolithography and chemical etching, to imprinting, and to 3D-printing) are reviewed. The reference list is extensive and (within each topic) it is arranged chronologically. Examples (with emphasis on those from the authors’ laboratory) are highlighted. Among them, they involve plasma miniaturization via microplasma formation inside micro-fluidic (and in some cases millifluidic) channels fabricated on 2D and 3D-chips. Questions addressed include: How small plasmas can be made? What defines their fundamental size-limit? How small analytical plasmas should be made? And what is their ignition voltage? The discussion then continues with the science, technology and applications of nanofluidics. The conclusions include predictions on potential future development of portable instruments employing either micro or nanofluidic channels. Such portable (or mobile) instruments are expected to be controlled by a smartphone; to have (some) energy autonomy; to employ Artificial Intelligence and Deep Learning, and to have wireless connectivity for their inclusion in the Internet-of-Things (IoT). In essence, those that can be used for chemical analysis in the field for “bringing part of the lab to the sample” types of applications

ADVANCES IN MICROELECTROMECHANICAL SYSTEMS

Microelectromechanical systems (MEMS) are integratedmicrodevices or systems combining electrical and mechanical components. The mechanical microcomponents either move inresponse to certain stimuli (sensors) or are initiated to performcertain tasks (actuators). The microelectronic components areused to control that motion or to obtain information from that motion. These systems can sense, control, actuate, and function individually or in arrays to generate effects on the microscale.These are fabricated using integrated circuit (IC) batch processing techniques making it possible to realise the complete systemon a chip. The miniaturisation of mechanical components bringsthe same benefit to mechanical systems that microfabrication brings to electronics. In a broader sense, technologies associatedwith MEMS include smart materials (e.g. shape memory alloys,ferroelectrics) and processes required to make MEMS components, integration of components to make MEMS devices (sensors,actuators, etc.) and applications that use MEMS devices. The MEMS are considered as building blocks for complex microrobots performing a variety of tasks and are used to make system swhich function very close to biological systems existing in nature.Defence Science Journal, 2009, 59(6), pp.555-556, DOI:http://dx.doi.org/10.14429/dsj.59.157

Micro Electromechanical Systems (MEMS) Based Microfluidic Devices for Biomedical Applications

Micro Electromechanical Systems (MEMS) based microfluidic devices have gained popularity in biomedicine field over the last few years. In this paper, a comprehensive overview of microfluidic devices such as micropumps and microneedles has been presented for biomedical applications. The aim of this paper is to present the major features and issues related to micropumps and microneedles, e.g., working principles, actuation methods, fabrication techniques, construction, performance parameters, failure analysis, testing, safety issues, applications, commercialization issues and future prospects. Based on the actuation mechanisms, the micropumps are classified into two main types, i.e., mechanical and non-mechanical micropumps. Microneedles can be categorized according to their structure, fabrication process, material, overall shape, tip shape, size, array density and application. The presented literature review on micropumps and microneedles will provide comprehensive information for researchers working on design and development of microfluidic devices for biomedical applications

Delamination of polyimide in hydrofluoric acid

Wet etching is a critical fabrication step for the mass production of micro and nanoelectronic devices. However, when an extremely corrosive acid such as hydrofluoric (HF) acid are used during etching, an undesirable damage might occur if the device includes a material that is not compatible with the acid. Polyimide thin films can serve as sacrificial/structural layers to fabricate freestanding or flexible devices. The importance of polyimide in microelectronics is due to its relatively low stress and compatibility with standard micromachining processes. In this work, a fast delamination process of a 4-μm-thin film of polyimide from a silicon substrate has been demonstrated. The films’ detachment has been performed using a wet-based etchant of HF acid. Specifically, the effect of HF concentration on the delamination time required to detach the polyimide film from the substrate has been investigated. This study is intended to provide the information on the compatibility of using polyimide films with HF, which can help in the design and fabrication of polyimide-based devices

Microsensors Based on MEMS Technology

Sensors play an important role in most of the common activities that occur in our daily lives. They are the building blocks of or microelectromechanical systems (MEMS). This combination of micromechanical structures, sensing elements, and signal conditioning is the beginning of a new era in sensor technology. Sensing systems incorporated with dedicated signal processing functions are called intelligent sensors or smart sensors. The present decade of new millennium will be the decade of smart systems or MEMS. The rapid rise of silicon MEMS recently was due to major advances in silicon microfabrication technology, especially surface micromachining, deep-reactive ion etching, and CMOS-integrated MEMS. In this paper, an overview of the currently available MEMS sensors, materials for sensors and their processing technologies, together with integraticm of sensors and electronics is presented