Nitride-Based Materials for Flexible MEMS Tactile and Flow Sensors in Robotics

Abstract

The response to different force load ranges and actuation at low energies is of considerable interest for applications of compliant and flexible devices undergoing large deformations. We present a review of technological platforms based on nitride materials (aluminum nitride and silicon nitride) for the microfabrication of a class of flexible micro-electro-mechanical systems. The approach exploits the material stress differences among the constituent layers of nitride-based (AlN/Mo, SixNy/Si and AlN/polyimide) mechanical elements in order to create microstructures, such as upwardly-bent cantilever beams and bowed circular membranes. Piezoresistive properties of nichrome strain gauges and direct piezoelectric properties of aluminum nitride can be exploited for mechanical strain/stress detection. Applications in flow and tactile sensing for robotics are described.

Nanobeams and AFM Subject to Piezoelectric and Surface Scale Effects

“…To work on the frequency domain, we need to introduce transfer function H( , , ) as being the Laplace transform of h( , , ) with respect to time (For inputs ( ) we seek outputs ( ) where ( ) = H ( ) with H defined in (17)). Thus…”

“…Conventional structural analysis methods assume ideal structures (free of irregularities) but material and/or geometrical variations in a structure may result in drastic changes in its dynamical behaviors. Diffusion-and reaction-controlled interfacial polymerization is an important and practical topic that is beyond our scope [15][16][17][18][19].…”

Development of a High-Density Piezoelectric Micromachined Ultrasonic Transducer Array Based on Patterned Aluminum Nitride Thin Film

“…Lead zirconate titanate (PZT) [18], zinc oxide (ZnO) [19], and aluminum nitride (AlN) [20][21][22][23] are widely used for piezoelectric layers to govern the performance of pMUTs. The lead-free AlN, having high mechanical hardness [24] and allowing to maintain piezoelectric properties at high temperatures (<900 • C), is a good candidate for a pMUT [25,26].…”

Captive-air-bubble aerophobicity measurements of antibiofouling coatings for underwater MEMS devices

“…Moreover, for applications involving flexible materials, it is important that the external coating has some specific characteristics: it should be conformal, lightweight, not fragile, and insulating. [1][2][3] Furthermore, one of the main issues related to submerged objects is the accumulation of microorganisms and macroorganisms on the solid surfaces, that is, biofouling, which could negatively affect the mechanical performance of the devices, especially in the field of MEMS micro-fabricated systems. 4 As a proof, Figure 1 shows a scanning electron microscope (by FEI Helios NanoLab 600i DualBeam) micrograph of a kapton-covered silicon substrate which we dried after 10 days of submersion in seawater: the surface is clearly populated by plenty of microorganisms, in particular bacteria (approximately 1 mm) and diatoms (approximately 10 mm), aggregating in complex chain-like structures.…”