SENSOR AND ACTUATOR

PRESENTED

BY

RAHUL

CONTENTS

PART I - PYRO ELECTRIC SENSOR

• PRINCIPLE

• SPECIFICATION

• APPLIATION

PART II - ULTRASONIC ACTUATOR

• PRINCIPLE

• SPECIFICATION

• APPLIATION

SENSOR - PRINCIPLE

Crystalline material generates a surface electric charge when exposed to heat from infrared radiation

Sensitive FET is build into the sensor to measure changes in charge

Filter window is added to sensor device to limit incoming radiation to the 8-14μm range

Configurations can cancel signals caused by vibration, temperature changes and sunlight.

PIR

SAMPLE CONFIGURATION

Infrared frequency range for human detection: 5-14μm

Filter to remove noise from power supplyMotion direction is detected by a more

positive/negative voltage response+5V required for accurate detectionFrensel Lens for Human Detection

SENSOE - SPECIFICATIONS

High Sensitivity and Excellent S/N ratioHigh Stability to the temperature changeSlight movement can be detectableNon directional sensing with wide field of

view (approx 41 degrees)High immunity to external noise

(Vibration, RFI, etc.)Supply voltage (3 to 15 V)Responsivity 3.3mV (typical)

SecurityLighting AppliancesHousehold or other AppliancesHeat SensingHuman or Mammal Detection

Viewing angle is regulated by the lensLimited to Temperature ranges detectably

below or above body temperature (~98.6 degrees)

Requires large amplification – low noise immunity

SENSOR - APPLICATION

SENSOR - LIMITATION

ACTUATOR - INTRODUCTION

An ultrasonic motor (USM) converts ultrasonic vibrations into linear or rotary motion.

USMs plays an important role a few niche markets where the size, torque, speed or other requirements could not be satisfied by the traditional EM motor.

USMs are often called solid state motors because they have very few moving parts and they can be fabricated like integrated circuits to be either macroscopic or microscopic.

ACTUATOR - PRINCIPLE

• One thing all USMs have in common is their use of piezoelectric material to transform electrical energy to mechanical energy.

• USMs typically use ceramics derived from lead-zirconate titanate (abbreviated PZT).

• After the PZT ceramic is shaped and fired, it is then electric field polarized. This allows the material to deform with a changing electric field

Linear USMs, sometimes called “tube” or “rod” USMs, also use piezoelectric metals or ceramics for actuation.Show here is a picture of New Scale Technologies tiny “Squiggle” motor.

The Squiggle motor weighs about 30g and boasts a stall force of 10N. Micro deformations also give resolutions as high as 1nm, and max speeds of 15mm/sec.

The Piezo LEGS motor, developed by MicroMo Electronics Inc., illustrates one popular technique for linear USM actuation.

• Like other USMs, the LEGS motor generates motion in discrete steps.

• 4 bimetallic metal/ceramic “legs” are positioned around a single nut on a threaded rod.

Applying voltage to a PZT leg causes it to change shape. This strain in the leg causes the nut to bend and shift on the threaded rod.

• By synchronizing the 4 legs an elliptical force pattern moves the rod in either the forward or reverse direction.

• Because deformations are small, several thousand pulses/sec are needed.

ACTUATOR - APPLICATION

• Camera lens autofocus.• Spacecraft planetary instruments.• Medical equipment (MRIs etc).• Small robotic joints.

ACTUATOR - ADVANTAGES

• Compact, lightweight, flexible and robust.• High positioning accuracy.• High low-speed torque and holding torque.• Unaffected by external electric or magnetic

fields.• Quiet drive system.• Hard brake with no backlash.• Variable stroke.• Quick response.

USMs have lots of potential for use in medical applications. One very promising research area is in medical diagnostic instruments.

The Robotics Institute of Carnegie Mellon University and the Division of Cardiac Surgery at the University of Pittsburgh are teaming up to create a tiny robot called the HeartLander.

MAJOR APPLICATION

The HeartLander is a tiny robot that surgeons could insert into a patient’s chest cavity through a minimally invasive incision. This tiny robot could then move along the surface

of the heart and perform interventions. The surgeon would be able to control every movement via a controller and monitor external to the patients body.

THANK YOU