Design, fabrication and test of integrated micro-scale vibration based electromagnetic generator

This paper discusses the design, fabrication and testing of electromagnetic microgenerators. Three different designs of power generators are partially microfabricated and assembled. Prototype A having a wire-wound copper coil, Prototype B, an electrodeposited copper coil both on a Deep Reactive Ion etched (DRIE) silicon, beam and paddle. Prototype C uses moving NdFeB magnets in between two microfabricated coils. The integrated coil, paddle and beam were fabricated using standard micro-Electro-Mechanical Systems (MEMS) processing techniques. For Prototype A, the maximum measured power output was 148 nW at 8.08 kHz resonant frequency and 3.9 m/s2 acceleration. For prototype B, the microgenerator gave a maximum load power of 23 nW for an acceleration of 9.8 m/s2, at a resonant frequency of 9.83 kHz. This is a substantial improvement in power generated over other microfabricated silicon based generators reported in literature. This generator has a volume of 0.1 cm3 which is lowest of all the silicon based microfabricated electromagnetic power generators reported. To verify the potential of integrated coils in electromagnetic generators, Prototype C was assembled. This generated a maximum load power of 5

Ion-track etched templates for the high density growth of nanowires of bismuth telluride and bismuth antimony telluride by electrodeposition

We report the electrochemical growth of high density arrays of n- type Bi2Te3 and p-type Bi0.5Sb1.5Te3 nanowires into ion-track etched polyimide-based Kapton membranes with a density of 5 x 109 wires/cm2. The average diameter of the nanowires is 80 nm with a length of 20 µm, which is comparable to the pore size and thickness of the employed Kapton foils. The electroplating parameters and microstructural properties are reported for the nanowires whilst thermoelectric properties have been investigated for thin films of Bi2Te3 and Bi0.5Sb1.5Te3

High density p-type Bi0.5Sb1.5Te3 nanowires by electrochemical templating through ion-track lithography

High density p-type Bi0.5Sb1.5Te3 nanowire arrays are produced by a combination of electrodeposition and ion-track lithography technology. Initially, the electrodeposition of p-type wBi(0.5)Sb(1.5)Te(3) films is investigated to find out the optimal conditions for the deposition of nanowires. Polyimide-based Kapton foils are chosen as a polymer for ion track irradiation and nanotemplating Bi0.5Sb1.5Te3 nanowires. The obtained nanowires have average diameters of 80 nm and lengths of 20 mu m, which are equivalent to the pore size and thickness of Kapton foils. The nanowires exhibit a preferential orientation along the {110} plane with a composition of 11.26 at.% Bi, 26.23 at.% Sb, and 62.51 at.% Te. Temperature dependence studies of the electrical resistance show the semiconducting nature of the nanowires with a negative temperature coefficient of resistance and band gap energy of 0.089 +/- 0.006 eV

Flexible screen printed thick film thermoelectric generator with reduced material resistivity

This work presents a flexible thick-film Bismuth Tellurium/Antimony Tellurium (BiTe/SbTe) thermoelectric generator (TEG) with reduced material resistivity fabricated by screen printing technology. Cold isostatic pressing (CIP) was introduced to lower the resistivity of the printed thermoelectric materials. The Seebeck coefficient (α) and the resistivity (ρ) of printed materials were measured as a function of applied pressure. A prototype TEG with 8 thermocouples was fabricated on flexible polyimide substrate. The dimension of a single printed element was 20 mm × 2 mm × 78.4 µm. The coiled-up prototype produced a voltage of 36.4 mV and a maximum power of 40.3 nW from a temperature gradient of 20°C

Elaboration et caractérisations microstructurale et électrique de tellurures de bismuth et d'antimoine élaborés par ultratrempe

MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF