A wireless ultrasound energy harvester based on flexible relaxor ferroelectric crystal composite arrays for implanted bio-electronics

Abstract

Implanted bio-electronic (IBE) devices such as pacemakers and neurostimulators have become increasingly important for therapeutic and diagnostic medical purposes. The life span of the IBE batteries ranges from several months...

Two orientation effects and large anisotropy of parameters in piezo-active 2–1–2 composites based on [0 1 1]-poled crystals

“…Advanced composites based on ferroelectric domainengineered single crystals (SCs) with important physical properties are of significant interest not only in an academic sense but also in a variety of transducer applications. Numerous two-component piezo-active SC-based composites, which were manufactured and studied recently, are characterised by either 2-2 [1][2][3] or 1-3 [4][5][6][7][8][9][10][11] connectivity written in terms of [12]. The connectivity indices such as 2-2 or 1-3 indicate [12,13] the number of axes of a rectangular coordinate system along which the first and second components of the composite are continuously distributed, respectively.…”

“…The aforementioned and other parameters enable one to use 2-2 composites, for instance, in hydrophone [2] and acoustic transducer [3] applications. The 1-3 composites studied recently are effective in various transducer [6,7,10,11] and energy-harvesting [9] applications, as elements of medical [4] and bio-electronic [9] devices. The presence of high-performance SC as the main piezoelectric component with high properties becomes a stimulus to study the 'composition-structure-property' relationships [13] that can facilitate specific piezotechnical applications of novel composites.…”

“…The presence of high-performance SC as the main piezoelectric component with high properties becomes a stimulus to study the 'composition-structure-property' relationships [13] that can facilitate specific piezotechnical applications of novel composites. As follows from recent papers on piezo-active composites, their main components are often chosen among perovskite-type solid-solution compositions, for instance, lead-containing (1−x)Pb(Mg 1/3 Nb 2/3 )O 3 −xPbTiO 3 (PMN-xPT) [5,6,9,10,14], Pb(In 1/2 Nb 1/2 )O 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 [1,7,11] or lead-free BaTiO 3 -CaTiO 3 -BaZrO 3 [8].…”

“…The 2-2 and 1-3 composite structures are well reproducible in the manufacturing sense [3,[8][9][10], so it is of interest to develop piezo-active composites [13,[15][16][17] and predict their effective (or homogenised, overall) physical properties by means of various methods. These methods include analytical methods, finite element modelling, resonator methods and matrix methods, which are applicable to heterogeneous electro-elastic media.…”