Optimized gradient-free PZT thin films for micro-actuators

Abstract

For its outstanding piezoelectric coefficients, thinfilm sol-gel Pb(Zr 0.52 , Ti 0.48 )O 3 (PZT) has been widely studied over the past few decades. In particular, the impact of Zr/Ti ratio control on e 31,eff coefficient has been investigated at low fields. Yet, when it comes to actuation, PZT films are used with electric fields higher than the coercive field. In this paper, the influence of Zr/Ti gradient reduction on e 31,eff coefficient is investigated in actuating conditions, ie under high fields.

Correlation between electric-field-induced phase transition and piezoelectricity in lead zirconate titanate films

“…Although efficient lead-free piezoelectric thin films have been recently proposed in the literature [1][2][3][4], lead-based films as Pb(Zr,Ti)O 3 (PZT) [5,6] or Pb(Mg,Nb)O 3 -PbTiO 3 (PMN-PT) [7] always exhibit the best piezoelectric properties. More specifically, they are strongly enhanced at the so-called morphotropic phase boundary (MPB) [8].…”

Piezoelectric Micro-pump with PZT Thin Film for Low Consumption Microfluidic Devices

“…On the BOX is deposited 20 nm-thick TiO 2 plus 100 nm-thick Pt, acting as bottom electrode. Then, 1.5 μm-thick sol-gel PZT layer is deposited by processing 28 successive layers, as depicted in [2]. The maximum processing temperature is 700 °C, required in order to crystallize PZT in the desired perovskite crystallographic structure.…”

“…Moreover, the packaging of ceramics is expensive. The development of PZT thin-films with high mechanical response for low voltage offers a suitable solution for both issues [2]. Few micropumps with piezoelectric thin films have been reported so far [3,4].…”

“…They show low performances mainly because they use non actuated valves, like diffusers or check-valves, and not optimized piezoelectric material, strongly limiting the range of applications. In this paper, we propose to combine the existing design of a micropump previously developed at CEA LETI [1] with optimized PZT thin films [2]. The general purpose of this study is to assess the propensity of PZT thin films to actuate micropumps at low voltage, and more specifically below 24 V, which is highly desired for medical applications.…”

Integration of PZT thin films on a microfluidic complex system

“…They show low performances mainly because they use non actuated valves, like diffusers or check-valves, and not optimized piezoelectric materials, strongly limiting the range of applications. In this paper, we propose to combine the existing design of a micropump previously developed at CEA LETI [1] with optimized PZT thin films [2]. The general purpose of this study is to assess the propensity of PZT thin films to actuate micropumps at low voltage, and more specifically below 24 V, which is highly desired for medical applications.…”