An electro-quasistatic analysis of an induction micromotor has been realized by using the Cell Method. We employed the direct Finite Formulation (FF) of the electromagnetic laws, hence, avoiding a further discretization. The Cell Method (CM) is used for solving the field equations at the entire domain (2D space) of the micromotor. We have reformulated the field laws in a direct FF and analyzed physical quantities to make explicit the relationship between magnitudes and laws. We applied a primal-dual barycentric discretization of the 2D space. The electric potential has been calculated on each node of the primal mesh using CM. For verification purpose, an analytical electric potential equation is introduced as reference. In frequency domain, results demonstrate the error in calculating potential quantity is neglected (<3‰). In time domain, the potential value in transient state tends to the steady state value.

In this work we analyse the temperature distribution in a conductor disk in transitory regime. The disk is in motion in a stationary magnetic field generated by a permanent magnet and so, the electric currents induced inside it generate heat. The system acts as a magnetic brake and is analysed using infrared sensor techniques. In addition, for the simulation and analysis of the magnetic brake, a new thermal convective matrix for the 3D Cell Method (CM) is proposed. The results of the simulation have been verified by comparing the numerical results with those obtained by the Finite Element Method (FEM) and with experimental data obtained by infrared technology. The difference between the experimental results obtained by infrared sensors and those obtained in the simulations is less than 0.0459%.

Reducing power consumption leads to improve wireless sensor autonomy, increase battery life, and reduce radiated power. State-of-the-art blood pressure sensors based on piezoresistive transducers in a full Wheatstone bridge configura tion uses low ohmic values because high sensitivity and low noise approach. In this work, the piezoresistance values are increased in order to reduce one order of magnitude the power consumption.The noise introduced by this improvement was proved that does not limit the accuracy for 8-bit applications. Therefore, a low power consumption pressure sensor with high sensitivity and low noise is proposed. Power consumption versus sensitivity tradeoff is analyzed in detail. I. IN T RODUCTIONWireless blood pressure sensors are especially suitable for surgery rooms, intensive care or post-anesthetic recovery units, even small laboratory animals. Low power consump tion is a critical point to improve the distance between the wireless sensor and monitoring equipments and improve the battery life of the sensors, reducing at the same time the power radiated to establish the wireless communication. State of-the-art blood pressure transducers, based on four resis tors in a full Wheatstone bridge configuration, are usually optimized for sensitivity [1]-[3] and linearity. Temperature effect on sensitivity in silicon piezoresistive transducer has been studied in detail in [3]- [5]. Analysis of the noise in piezoresistive transducer has been presented in [5]. Most of the piezoresisitive transducer are ion-implanted into a thin silicon monocrystalline membrane. Ty pical values are in the range between 100 fl and 3 kfl, powered between 3 V and 5 V. This means a power consumption between 3 m W and 250 m W, typically 20 mW, only for the full Wheatstone bridge without the required signal conditioning circuit -a signal conditioning circuit with at least one operational amplifier is required.In this work, the piezoresistance ohmic values are increased in order to reduce the power consumption. It was proved that the noise introduced by this improvement does not limit the accuracy for 8-bit applications. The achieved power con sumption results are below 322 /-l W, including both the full Wheatstone bridge (62/-lW) and the signal conditioning sys tem, for a mixed signal technology of 1.0 /-lm CMOS process, including integrated sensors -XC 10 technology process from XFAB. This work proposes optimal tradeoff design points for piezoreslstlve transducer and sensor in terms of sensitivity, power consumption and noise. This paper is organized as follows. In Section II mechanical behavior of a diaphragm -pressure sensor-is analyzed in detail. In addition, the layout dimensions and positions of several piezoresistances -250, 500 and 1000 kfl-are calculated. The analysis of both sensitivity and power consumption of a full Wheatstone bridge and differential amplifier circuit to achieve optimum power and sensitivity design points is presented in Section m. Finally, conclusions are presented in Section IV. II. ELECTROMECHAN...

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This paper analyzes the influence on the force density of the spatial harmonics of the excitation voltage signal on each electrode of an electrostatic induction micromotor. We have used the lumped parametric equivalent circuit [7] and demonstrated that the spatial harmonics are attenuated from stator to rotor. Index Terms-Electrostatic induction micromotor, spatial harmonics, parametric equivalent circuit. I. NOMENCLATURE Symbol Name Unit a Height of dielectric a, air (m) b Height of dielectric b, rotor (m) C 1 Capacitance 1 (F/m) C 2 Capacitance 2 (F/m) G′ 2 Conductance 2 (S/m) G′ r Variable Conductance (S/m) k Number of waves per metre j Imaginary unity-S Slip-T t Force density tangential component (N/m 2) v Linear speed of mobile part (m/s) V Interelectrodic voltage (V) V 0 Supply voltage (V) V 1 Voltage in node 1 (V) V 2 Voltage in node 2 (V) ε a Permittivity of the dielectric a (F/m) ε b Permittivity of the dielectric b (F/m) ε eff Effective permittivity (F/m) ω Angular frequency of the signal (Hz) σ a Conductivity of the dielectric a (S/m) σ b Conductivity of the dielectric b (S/m) σ eff