Shape-Memory Micropumps

Abstract

Motivated by many experimental efforts to develop suitable shape-memory micropumps, we propose a multiscale framework to study the behavior of pressurized films. We use recoverable deflection as a measure to design large stroke micropumps and develop a model to estimate it. We show that the recoverable deflection of a polycrystalline shape-memory film depends on the transformation strain of the underlying martensitic transformation, the texture and especially on the size effects. We find that flat grains are preferable to long grains in columnar films concerning the purpose of large recoverable strain. We also show that common sputtering texture is not ideal for recoverable deflection in both Ti-Ni and Cu-based shape-memory films. It turns out that {100} Cu-based films may have better behavior than Ti-Ni films. We conclude with comparison with experiment.

Thermomechanics of shells undergoing phase transition

“…Shu (2002), Bhattacharya and James (2005) and Tobushi et al (2009), and books by Bhattacharya (2003), Lagoudas (2008) and Miyazaki et al (2009).…”

“…Another interesting example of PT in thin-walled structures are tents and tunnels discovered and investigated in detail in , Hane (1999), James and Hane (2000), Shu (2000Shu ( , 2002 and Bhattacharya and James (2005). For example, tent-or dome-shaped structures appear in martensitic thin films during PT.…”

A homogenized free energy model for hysteresis in thin-film shape memory alloys

“…Scaling these mesoscopic theories to macroscopic levels usually is computationally intensive; therefore, for macroscopic predictions, these models are generally not intended for on-line engineering nor control applications. Recently, micromechanical models have been developed specifically for thin-film SMAs [8,13,53,99].…”

Effect of actuation sequence on flow rates of peristaltic micropumps with PZT actuators

“…Of these various devices, micropumps are of vital importance in many biological applications (Laser and Santiago 2004). Various micropumps have been proposed in recent years based on a variety of actuation mechanisms, including piezoelectric (Andersson et al 2001), shape memory alloys (Shu 2002), electrostatics (Xie et al 2004;Francais and Dufour 1998), thermal actuation (Tsai and Lin 2002) and rotary magnetics (Ahn and Allen 1995). Of these actuation schemes, the use of piezoelectric actuators is particularly attractive due to their simple structure, high output power density and high actuation force (Nguyen et al 2002).…”