Biomimetics of underwater hair cell sensing

Hair cells are ubiquitous in nature. These natural and efficient mechanoreceptors are exploited as efficient transducers for flow sensing and chemical sensing in many living systems, ranging from cells to aquatic animals. In aquatic environment hair cells are probably the most effective mechanism of sensing and environment perception. Mimicking these mechanoreceptors and their structure and behavior for developing MEMS artificial hair cells (AHC) could be a powerful approach for producing efficient underwater sensors and technologies. In this paper we review the most recent approaches and designs to realize waterproof hair cell-like mechanotransducers for applications in underwater flow and acoustic sensing, mimicking the so-called “lateral line” in fishes. Recent developments for the achievement of artificial lateral lines to be applied in underwater autonomous vehicles will be highlighted. Finally research strategies to obtain artificial hair cells biosensing in liquid environment will be introduced

Diagnostic ultrasound probes: a typology and overview of technologies

The routine clinical use of diagnostic ultrasound (US) has spread considerably worldwide in recent decades. This is due in large part to the availability of US probes that enable a wide range of clinical applications as well as provide performance benefits arising from technological improvements. This paper describes the current commercially available US probe types, lists some of their clinical applications and briefly explains the technologies that are responsible for recent enhancements in image quality and ergonomics. Our intention is to summarize information that will allow healthcare professionals to select the appropriate probe for the intended use and the desired performance-price ratio

A 2D approach to surface-tension-confined fluidics on parylene C

Parylene C-based 2D STC fluidics, where pure water and water-based solutions can flow strictly confined by differences in surface energy

Mechanical Properties Tunability of Three-Dimensional Polymeric Structures in Two-Photon Lithography

none8nononeLemma, Enrico Domenico; Rizzi, Francesco; Dattoma, Tommaso; Spagnolo, Barbara; Sileo, Leonardo; Qualtieri, Antonio; De Vittorio, Massimo; Pisanello, FerruccioLemma, Enrico Domenico; Rizzi, Francesco; Dattoma, Tommaso; Spagnolo, Barbara; Sileo, Leonardo; Qualtieri, Antonio; De Vittorio, Massimo; Pisanello, Ferrucci

PDMS ring-spring soft probe for nano-force biosensing

We present an innovative design for a flexible probe to study mechanisms of biological force sensing and force generation in the piconewton to micronewton range. Made of polydimethylsiloxane (PDMS) and employing a novel ring-spring section with adjustable size, the device works both as a force sensor and force actuator by precise calibration of its tunable stiffness and optical measurement of ring deformation. In addition, the tip geometry of the probe can be properly shaped to fit the anatomical profile of the sensory receptor of interest and to reproduce the in vivo stimulation. Finally, use of Finite Element Method (FEM) modal analysis confirms that the resonance frequencies of probes are outside the frequency range of interest for many sensory systems. © 2015 IEEE

A thermo-activated tactile micro-actuator for displays

In this work we report the design, the fabrication and the characterization of an innovative soft tactile micro-actuator, also called TAXEL (TActile piXEL), which is developed to be integrated in a portable tactile display for providing text content and graphical information to visually impaired people through the sense of touch. It exploits a thermo-active approach, by taking inspiration from common thermometers: the actuator is activated by the thermal deformation of an active material, namely the metallic alloy Galinstan© determined by heating the alloy through an underlying metallic resistor designed to work as a heater. The microfabrication of TAXELs is achieved in several steps consisting in heater fabrication, in SU8 micro chambers fabrication, in the deposition of Galinstan® inside and sealing by a PDMS membrane. Measurements of the TAXEL deformation have been accomplished by measuring the displacement of the PDMS sealing membrane, which is promoted by the expansion of the heated Galinstan® drop. These measurements have been achieved by using the Laser Doppler Vibrometer in the “topography mode “and revealed a total displacement of 50 μm when a tension of 2.4 V is applied at taxel terminals and, according to the Joule's law, a power converted from electrical energy to thermal energy of 7,2 W. © 2018 Elsevier B.V