Small doesn't necessarily mean scrawny. With petite components, it's all about torque density and packing power into small spaces. When your next project calls for mini but mighty options, consider the following tools to help downsize your designs.

Plug-in PLC

Solves-It! programmable logic controllers offer a solution where a small yet versatile controller is needed. Units mount in any standard 11-pin octal base and program in ladder logic with function block diagrams. The base unit has four inputs, four outputs, and four programmable LED indicators. It is suitable for machine control and monitoring applications, especially where panel space is limited.
Divelbiss Corp.
www.divelbiss.com

Sub-miniature stepping motor

Compact and lightweight 1.8° NEMA 8 bipolar hybrid stepper motors provide flexibility in applications with limited space, such as medical devices and small machinery. Measuring just 20 mm square by as little as 30 mm long, these motors produce high speed and torque in a sub-miniature RoHS compliant package. In many applications, torque levels reached with these stepmotors make them a cost effective alternative to servos.
Nippon Pulse America Inc.www.nipponpulse.com

Kit for micro brushless dc motors

The Microsystems Starter Kit contains drive electronics, an adaptor board, and a dc brushless motor from the series 0206…B, 0308…B, or 1202…BS/BH. Each motor easily connects to the adaptor board, which contains an integrated oscillator for speed control. The PWM frequency is 500 kHz. As an example of the motor choices, the Penny motor series 1202…BH is a flat brushless dc motor with a diameter of 12 mm, a 2 mm height, and a weight of just 1.1 grams.
MicroMo Electronics Inc.
www.micromo.com

Microstepping driver

The compact MForce PowerDrive delivers a per-phase output current of 7 A peak or 5 A RMS and includes an integrated heat sink and user-friendly pluggable locking connectors. The driver comes with an optional programmable motion controller or variable speed controller and accepts up to 20 resolution settings, from full to 256 microsteps per full step. Input voltage range is 12 to 75 Vdc and operating temperature range is from -40° to 85° C.
Intelligent Motion Systems Inc.
www.imshome.com

Internal rotor motor

EC-I 40 electronically commutated internal rotor motors are short, but highly dynamic. These brushless grooved motors feature low inertia, minimal detent, robust bearings, and compact construction. High-powered magnets ensure significant power density, providing exceptional speed stability under load. Motors are available with a 40 mm diameter in two lengths — 26 mm (50 W) and 36 mm (70 W).
Maxon Precision Motors Inc.
www.maxonmotorusa.com

Linear actuator

35000 series (size 14) double stack hybrid linear actuators take up just 1.4 sq in. and come in three designs — captive, non-captive, and external linear versions. They are available in a range of resolutions from .0158 mm to .127 mm per step, and can be microstepped for even finer resolution. Engineered thermoplastics in the rotor drive nut and a stainless acme lead screw help ensure reliability. Custom designs are also available.
Haydon Switch & Instrument Inc.
www.hsi-inc.com

Vibrating micro motor

The BSY series dc motor is a vibrating micro motor with a profile of just 3.4 mm in a SMD package. This little motor would work well in applications requiring a small footprint on surface mount circuit boards, such as mobile phones and medical devices. The motor measures 11 mm in length, with a body 4.4 mm wide by 3.4 mm high off the mounting surface. Typical speed is 14,000 rpm and standard operating voltage is 2.7 Vdc.
Sanyo DC Micro Motor Division
http://us.sanyo.com/industrial/micro_motors

Compact gearmotor

This 12 Vdc gearmotor has a 2.14 in. diameter and is 7.7 in. long, with a total weight of less than 7 lb. Output torque is rated to 125 lb-in. continuous and 178 lb-in. peak, with motor windings for 24, 36, 48, and 90 V also available. The new motor is IP54 rated for use in harsh environments and easily mounts using four “face mount” M5 threaded holes. This gearmotor accepts any 12 Vdc source, including battery power.
Midwest Motion Products
www.midwestmotion.com

Tiny tools

Just how small is small? It all depends on the application. A compact motor that fits on a packaging line is a universe away from the tiny motors used in cell phone cameras or handheld medical devices. Miniaturization has taken place across a wide range of industries and scientific disciplines as well — think mechanical, optical, and electronic components.

For many in industry, the ultimate goal is smaller, lighter, and cheaper end products. Another way to think about miniaturization is density — torque and force density in mechanical components and processing power density in microelectronics, as chips continue to get smaller and smarter.

Then there's nanotechnology and the world of nanoscale machines that operate on a molecular level. While miniaturization and nanotechnology are not the same thing, they are related. Miniaturization is easily defined — things getting smaller — while nanotechnology explores the way that properties change and can be made to act when manipulated at the atomic or molecular level. Things like self-cleaning glass and stain-free clothing that repels moisture involve nanotechnology and mimic some of what's found in nature, such as the processes going on in self-cleaning lotus plants or nasturtium leaves.

For engineers, it's important and inspiring to keep up with developments in the nanoworld. Check out these websites:

Foresight Nanotech Institute foresight.org
Georgia Institute of Technology nano.gatech.edu
Institute of Nanotechnology nano.org.uk
Lawrence Berkeley National Lab lbl.gov
Nanotechnology Now nanotech-now.com
National Nanotechnology Initiative nano.gov
Purdue University purdue.edu/discoverypark
University of Illinois micro.uiuc.edu