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This paper discusses the design, fabrication and testing of electromagnetic microgenerators. Three different designs of power generators are partially micro-fabricated 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 micro-fabricated 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/s 2 acceleration. For Prototype B, the microgenerator gave a maximum load power of 23 nW for an acceleration of 9.8 m/s 2 , at a resonant frequency of 9.83 kHz. This is a substantial improvement in power generated over other micro-fabricated silicon-based generators reported in literature. This generator has a volume of 0.1 cm 3 which is lowest of all the silicon-based micro-fabricated 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 586 nW across 110 load at 60 Hz for an acceleration of 8.829 m/s 2 .

A series of alkylchalcogenostibines have been synthesised and employed as precursors for the chemical vapour deposition of Sb2Te3 and Sb2Se3. Variations in substrate and temperature give different film morphologies, and patterned arrays can be deposited using substrate selectivity.

This paper presents a silicon microgenerator, fabricated using standard silicon micromachining techniques, which converts external ambient vibrations into electrical energy. Power is generated by an electromagnetic transduction mechanism with static magnets positioned on either side of a moving coil, which is located on a silicon structure designed to resonate laterally in the plane of the chip. The volume of this device is approximately 100 mm 3 . ANSYS finite element analysis (FEA) has been used to determine the optimum geometry for the microgenerator. Electromagnetic FEA simulations using Ansoft's Maxwell 3D software have been performed to determine the voltage generated from a single beam generator design. The predicted voltage levels of 0.7-4.15 V can be generated for a two-pole arrangement by tuning the damping factor to achieve maximum displacement for a given input excitation. Experimental results from the microgenerator demonstrate a maximum power output of 104 nW for 0.4g (g=9.81 m s À1 ) input acceleration at 1.615 kHz. Other frequencies can be achieved by employing different geometries or materials.

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† Electronic supplementary information (ESI) available: Details of substrate preparation and characterisation of the Bi 2 Te 3 thin lms; thermogravimetric analysis (TGA) of [BiCl 3 (Te n Bu 2) 3 ], SEM images of thin lms of Bi 2 Te 3 , Raman analysis of Bi 2 Te 3 thin lms, WDX compositional analysis of Bi 2 Te 3 thin lms, and microfocus and pole gure XRD analysis of micro-scale Bi 2 Te 3 arrays, lattice parameters rened for Bi 2 Te 3 grown on different substrates. See

High density p-type Bi 0.5 Sb 1.5 Te 3 nanowire arrays are produced by a combination of electrodeposition and ion-track lithography technology. Initially, the electrodeposition of p-type Bi 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 Bi 0.5 Sb 1.5 Te 3 nanowires. The obtained nanowires have average diameters of 80 nm and lengths of 20 mm, 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 AE 0.006 eV.