Enric Montane

Smart Power Integrated Circuit for a Piezoelectric Miniature Robot

A BCD technology (Bipolar, CMOS, DMOS) is used to implement a high voltage smart power integrated circuit in order to obtain a fully integrated Smart Powered Piezoactuator Unit (SPU) for a new generation of miniature robots with sizes around 1 cm3. The integrated circuit is based on a mixed-mode circuit with power analogue output circuitry and digital input control circuitry. A specific driving system strategy is defined based on ICs assembled on-board with a serial communication interface. This minimizes the number of wires connecting the miniature robot to improve the robot motion performances and is a first step towards fully autonomy. Six samples of the ICs have been assembled onto a driving platform and tested with good results.

A MOSFET-only second order delta-sigma modulator for capacitive sensor interfaces

A 14-bit MOSFET-only 2/sup nd/ order /spl Delta/-/spl Sigma/ modulator has been implemented in a 0.7 /spl mu/m CMOS process for capacitive sensors interfaces. A switched capacitor architecture that allows the substitution of linear capacitors by MOS capacitors has been developed. These circuits have low cost fabrication, small area, and high matching. This proposal was tested comparing two different /spl Delta/-/spl Sigma/ modulators, one with linear capacitors and the MOS-only version. Similar results were obtained for both modulators.

High accuracy piezoelectric-based microrobot for biomedical applications

Today, the use of robots for self acting tasks in applications ranging from biology and medicine to microsystems technology demand miniaturized dimensions and high-precision handling techniques. Transport and manipulation of biological cells or assembly of micromechanical parts are the best-suited applications for microrobots with sizes about cm/sup 3/. The kind of actuator used for locomotion is a crucial part when a miniaturised robot for micropositioning and micromanipulating is developed. Demands on low cost, high resolution and small size make piezoceramic actuators an attractive alternative. A Smart Piezoactuator Unit (SPU) has been developed and will be used in a new generation of microrobots with a size of a few cm/sup 3/. The main characteristics of this Smart Piezoactuator Unit are presented in this paper. An integrated circuit containing power drivers and a digital control system with a fast serial interface protocol has been designed. Integrating this circuit close to the piezoceramic actuators results in a compact and a minimal number of connecting wires to the robot.

Smart power integrated circuits to drive piezoelectric actuators for a cm3 microrobot system

Today, the use of robots for self acting tasks in applications ranging from biology and medicine to microsystems technology demand miniaturized dimensions and high-precision handling techniques. A lot of these tasks have been carried out by humans, but the manual capabilities are restricted to certain tolerances. Transport and manipulation of biological cells or assembly of micromechanical parts are the best suited applications for microrobots with sizes about cm3. Low cost and high-resolution actuators are critical performances which determine to choose piezoceramic materials as more suitable for micropositioning and micromanipulation units of a cm3 microrobot. Smart Piezoactuator Unit (SPUs) as a basic element of a new generation of cm3 microrobots have been developped. The main characteristic of this proposed Smart Piezoactuator Unit system is the integration of driving circuitry with the piezoelectric actuators and to include a serial communication interface to minimize the number of power and command wires. Micropositioning and micromanipulation units are developed combining properly 6 Smart Piezoactuator Units each one. A BCD technology (Bipolar, CMOS, DMOS) is used to design high voltage smart power integrated circuit for these Smart Piezoactuator Units. Using this technology we integrate in the same chip 4 power drivers with its control and protection circuitry.

A compact temperature sensor for a 1.0 μm CMOS technology using lateral p-n-p transistors

Abstract A compact temperature sensor using lateral p-n-p bipolar transistors has been fabricated and tested in a standard 1.0 μm digital n-well CNIOS process. Like their n-p-n counterparts in p-well processes, these lateral p-n-p devices exhibit good lateral β. The accuracy of the temperature sensor is close to the performances obtained in bipolar technology, an output proportional to absolute temperature is obtained (0.54mV/K) from 0 to +70°C, although the sensor can be used in wide-ranging applications after curvature correction. The device has an area of only 0.018 mm 2 .

Complimentary metal-oxide semiconductor linear photosensor array for 3-D reconstruction applications

A linear 128-photosensor array in a complimentary metal-oxide semiconductor (CMOS) standard technology is presented. The characteristics of the pixels are high voltage at the output in the range of 0 to 3.5 V and a pixel memory with the possibility of multiple readouts without significant degradation of information. The ASIC also includes a selection logic to select the pixel to be read. Using this CMOS photodetector array, we also present a low-cost prototype for the distance measurement and 3-D reconstruction of near and small objects, where the optical triangulation method used is appropriate. Good acquisition results are obtained in the experimental test.

Electronic circuitry development in a micropyrotechnic system for micropropulsion applications

An electronic circuitry is proposed and implemented to optimize the ignition process and the robustness of a microthruster. The principle is based on the integration of propellant material within a micromachined system. The operational concept is simply based on the combustion of an energetic propellant stored in a micromachined chamber. Each thruster contains three parts (heater, chamber, nozzle). Due to the one shot characteristic, microthrusters are fabricated in 2D array configuration. For the functioning of this kind of system, one critical point is the optimization of the ignition process as a function of the power schedule delivered by electronic devices. One particular attention has been paid on the design and implementation of an electronic chip to control and optimize the system ignition. Ignition process is triggered by electrical power delivered to a polysilicon resistance in contact with the propellant. The resistance is used to sense the temperature on the propellant which is in contact. Temperature of the microthruster node before the ignition is monitored via the electronic circuitry. A pre-heating process before ignition seems to be a good methodology to optimize the ignition process. Pre-heating temperature and pre-heating time are critical parameters to be adjusted. Simulation and experimental results will deeply contribute to improve the micropyrotechnic system. This paper will discuss all these point.

CMOS array of photodiodes with electronic processing for 3D optical reconstruction

It is well known that laser time-of-flight (TOF) and optical triangulation are the most useful optical techniques for distance measurements. The first one is more suitable for large distances, since for short range of distances high modulation frequencies of laser diodes (»200-500MHz) are needed. For these ranges, optical triangulation is simpler, as it is only necessary to read the projection of the laser point over a linear optical sensor without any laser modulation. Laser triangulation is based on the rotation of the object. This motion shifts the projected point over the linear sensor, resulting on 3D information, by means of the whole readout of the linear sensor in each angle position. On the other hand, a hybrid method of triangulation and TOF can be implemented. In this case, a synchronized scanning of a laser beam over the object results in different arrival times of light to each pixel. The 3D information is carried by these delays. Only a single readout of the linear sensor is needed. In this work we present the design of two different linear arrays of photodiodes in CMOS technology, the first one based on the Optical triangulation measurement and the second one based in this hybrid method (TFO). In contrast to PSD (Position Sensitive Device) and CCDs, CMOS technology can include, on the same chip, photodiodes, control and processing electronics, that in the other cases should be implemented with external microcontrollers.

MOSFET-based temperature sensor for standard BCD smart power technology

Two on-chip temperature sensors for smart power BCD technology were compared. Temperature sensors based on bipolar transistors failed when DMOS power transistors were working under AC conditions because of substrate-coupled effects. An alternative MOSFET-based temperature sensor derived from a supply-independent CMOS bias source may overcome the problems associated with BCD technology.

Test structures for CMOS-compatible silicon pressure sensor reliability characterization

Pressure sensors structures have been fabricated in a commercial CMOS foundry technology using a post-processing for back-side wafer micro machining. In order to predict the sensor response to an externally applied differential pressure, the structure behavior has been simulated by Finite Element Methods. The design and fabrication of test structures for these sensor devices is described. Experimental results obtained using these structures are presented.