How Relays Work

How Relays Work

Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized. When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state. 
Relays are generally used to switch smaller currents in a control circuit and do not usually control power consuming devices except for small motors and Solenoids that draw low amps. Nonetheless, relays can "control" larger voltages and amperes by having an amplifying effect because a small voltage applied to a relays coil can result in a large voltage being switched by the contacts. 
Protective relays can prevent equipment damage by detecting electrical abnormalities, including overcurrent, undercurrent, overloads and reverse currents. In addition, relays are also widely used to switch starting coils, heating elements, pilot lights and audible alarms. 

Electromechanical Relays vs Solid State Relays

Relays are either electromechanical relays or solid-state relays. In electromechanical relays (EMR), contacts are opened or closed by a magnetic force. With solid-state relays (SSR), there are no contacts and switching is totally electronic. The decision to use electromechanical or solid state relays depends on an application's electrical requirements, cost constraints and life expectancy. Although solid-state relays have become very popular, electromechanical relays remain common. Many of the functions performed by heavy-duty equipment need the switching capabilities of electromechanical relays. Solid State Relays switche the current using non-moving electronic devices such as silicon controlled rectifiers. 
These differences in the two types of relays result in advantages and disadvantages with each system. Because solid state relays do not have to either energize a coil or open contacts, less voltage is required to "turn" Solid State Relays on or off. Similarly, Solid State Relays turn on and turn off faster because there are no physical parts to move. Although the absence of contacts and moving parts means that Solid State Relays are not subject to arcing and do not wear out, contacts on Electromechanical Relays can be replaced, whereas entire Solid State Relays must be replaced when any part becomes defective. Because of the construction of Solid State Relays, there is residual electrical resistance and/or current leakage whether switches are open and closed. The small voltage drops that are created are not usually a problem; however, Electromechanical Relays provide a cleaner ON or OFF condition because of the relatively large distance between contacts, which acts as a form of insulation

Electromechanical Relays

Basic parts and functions of electromechanical relays include: 

1. Frame: Heavy-duty frame that contains and supports the parts of the relay.
2. Coil: Wire is wound around a metal core. The coil of wire causes an electromagnetic field.
3. Armature: A relays moving part. The armature opens and closes the contacts. An attached spring returns the armature to its original position.
4. Contacts: The conducting part of the switch that makes (closes) or breaks (opens) a circuit.

Relays involve two circuits: the energizing circuit and the contact circuit. The coil is on the energizing side; and the relays contacts are on the contact side. When a relays coil is energized, current flow through the coil creates a magnetic field. Whether in a DC unit where the polarity is fixed, or in an AC unit where the polarity changes 120 times per second, the basic function remains the same: the magnetic coil attracts a ferrous plate, which is part of the armature. One end of the armature is attached to the metal frame, which is formed so that the armature can pivot, while the other end opens and closes the contacts. Contacts come in a number of different configurations, depending on the number of Breaks, poles and Throws that make up the relay. For instance, relays might be described as Single-Pole, Single-Throw (SPST), or Double-Pole, Single-Throw (DPST). These terms will give an instant indication of the design and function of different types of relays. 

• Break -This is the number of separate places or contacts that a switch uses to open or close a single electrical circuit. All contacts are either single break or double break. A single break (SB) contact breaks an electrical circuit in one place, while a double break (DB) contact breaks it in two places. Single break contacts are normally used when switching lower power devices such as indicating lights. Double break contacts are used when switching high-power devices such as solenoids.
• Pole -This is the number of completely isolated circuits that relays can pass through a switch. A single-pole contact (SP) can carry current through only one circuit at a time. A double-pole contact (DP) can carry current through two isolated circuits simultaneously. The maximum number of poles is 12, depending upon a relays design.
• Throw -This is the number of closed contact positions per pole that are available on a switch. A switch with a single throw contact can control only one circuit, while a double-throw contact can control two.

Types of Relyas: Electromechanical

1. General Purpose Relays are electromechanical switches, usually operated by a magnetic coil. General purpose relays operate with AC or DC current, at common voltages such as 12V, 24V, 48V, 120V and 230V, and they can control currents ranging from 2A-30A. These relays are economical, easy to replace and allow a wide range of switch configuration.
2. Machine Control Relays are also operated by a magnetic coil. They are heavy-duty relays used to control starters and other industrial components. Although they are more expensive than general purpose relays, they are generally more durable. The biggest advantage of machine control relays over general purpose relays is the expandable functionality of Machine Control Relays by the adding of accessories. A wide selection of accessories is available for machine control relays, including additional poles, convertible contacts, transient suppression of electrical noise, latching control and timing attachments.
3. Reed Relays are a small, compact, fast operating switch design with one contact, which is NO. Reed Relays are hermetically sealed in a glass envelope, which makes the contacts unaffected by contaminants, fumes or humidity, allows reliable switching, and gives contacts a higher life expectancy. The ends of the contact, which are often plated with gold or another low resistance material to increase conductivity, are drawn together and closed by a magnet. Reed relays are capable of switching industrial components such as solenoids, contactors and starter motors. Reed relays consists of two reeds. When a magnetic force is applied, such as an electromagnet or coil, it sets up a magnetic field in which the end of the reeds assume opposite polarity. When the magnetic field is strong enough, the attracting force of the opposite poles overcomes the stiffness of the reeds and draws them together. When the magnetic force is removed, the reeds spring back to their original, open position. These relays work very quickly because of the short distance between the reeds.

Solid State Relays

Solid state relays consist of an input circuit, a control circuit and an output circuit. The Input Circuit is the portion of a relays frame to which the control component is connected. The input circuit performs the same function as the coil of electromechanical relays. The circuit is activated when a voltage higher than the relays specified Pickup Voltage is applied to the relays input. The input circuit is deactivated when the voltage applied is less than the specified minimum Dropout voltage of the relay. The voltage range of 3 VDC to 32 VDC, commonly used with most solid-state relays, makes it useful for most electronic circuits. The Control Circuit is the part of the relay that determines when the output component is energized or de-energized. The control circuit functions as the coupling between the input and output circuits. In electromechanical relays, the coil accomplishes this function. A relays Output Circuit is the portion of the relay that switches on the load and performs the same function as the mechanical contacts of electromechanical relays. Solid-state relays, however, normally have only one output contact.

Types of Relays: Solid State

1. Zero-Switching Relays - relays turns ON the load when the control (minimum operating) voltage is applied and the voltage of the load is close to zero. Zero-Switching relays turn OFF the load when the control voltage is removed and the current in the load is close to zero. Zero-Switching relays are the most widely used.
2. Instant ON Relays - turns ON the load immediately when the pickup voltage is present. Instant ON Relays allow the load to be turned ON at any point in it's up and down wave.
3. Peak Switching Relays - turns ON the load when the control voltage is present, and the voltage of the load is at its peak. Peak Switching relays turn OFF when the control voltage is removed and the current in the load is close to zero.
4. Analog Switching Relays - has an infinite number of possible output voltages within the relays rated range. Analog switching relays have a built in synchronizing circuit that controls the amount of output voltage as a function of the input voltage. This allows a Ramp-Up function of time to be on the load. Analog Switching relays turn OFF when the control voltage is removed and current in the load is near zero.

A Relays Contact Life

A relays useful life depends upon its contacts. Once contacts burn out, the relays contacts or the entire relay has to be replaced. Mechanical Life is the number of operations (openings and closings) a contact can perform without electrical current. A relays mechanical life is relatively long, offering up to 1,000,000 operations. A relays Electrical life is the number of operations (openings and closings) the contacts can perform with electrical current at a given current rating. A relays Contact electrical life ratings range from 100,000 to 

Baby eating lemon first time so funny

How Much Can You REALLY Save with Energy Efficient Improvements?

How Much Can You REALLY Save with Energy Efficient Improvements?

Colorful leaves, cooler weather, cozy sweaters, pumpkin spice everywhere—it's definitely fall! While you're snuggling in and sipping a warm drink, we hope you'll join us this October and take action to save energy—and money—at home. 

October is Energy Action Month, so it's the perfect time to get serious about energy savings. Not only is the weather perfect for taking on home improvement projects, but the timing is just right given that colder weather is coming soon. Taking steps now will mean greater comfort and savings by the time pumpkin spice gives way to peppermint. 

To get you started, we've put together a list of specific actions you can take to save energy and water in your home, along with the potential annual savings for all of them. Be sure to check out the ideas below the table as well to really maximize your savings.

RECOMMENDED ACTION	POTENTIAL SAVINGS (AS A PERCENTAGE OF UTILITY BILLS)	AVERAGE ANNUAL SAVINGS IN $ (BASED ON EIA AVERAGE END-USE EXPENDITURES*; ACTUAL SAVINGS WILL VARY)
Install exterior low-e storm windows	12%-33% annually on heating and cooling bills	$100-$274
Seal uncontrolled air leaks	10%-20% on annual heating and cooling bills	$83-$166
Plant shade trees	15%-50% of annual air conditioning costs	$35-$119
Use a power strip for electronic equipment and turn it off when not in use	Up to 12% of electric bill per year	$100
Replace an older toilet that uses 6 gallons per flush with a WaterSense model		$100
Turn back your thermostat 7°-10°F for 8 hours a day	Up to 10% annually on heating and cooling bills	$83
Weatherstrip double-hung windows	5%-10% annually on heating and cooling bills	$42-$83
Replace your home's five most frequently used light fixtures or bulbs with models that have earned the ENERGY STAR	9% on electricity bill annually	$75
Lower water heating temperature	Save 4%-22% annually on your water heating bill	$12-$60
Insulate water heater tank	Save 7%-16% annually on water heating bill	$20-$45
Fix leaky faucets; one drip per second wastes 1,661 gallons of water		$35
Use sleep mode and power-management features on your computer	Up to 4% of annual electric bill	$30
Insulate hot water pipes	Save 3%-4% annually on water heating bill	$8-$12
**TOTAL POTENTIAL SAVINGS		$723-$1,182

*Average annual energy expenditures per household in the U.S. are as follows: space heating: $593; water heating: $280; air conditioning: $237; refrigerators: $153; other (lighting and electricity): $827
**All actual savings will vary depending on home, climate, products, and use.

The above list is just a sampling of the potential savings you could see by making smart energy choices in your home. Not all of these improvements will be possible for everyone, and savings will vary.

If you want to understand how to get the biggest bang for your buck, we recommend a professional home energy audit, which can help you pinpoint areas where your home is losing energy and which improvements will save you the most money. Making upgrades recommended in a home energy audit—and many of the items above would likely be included in your recommendations—could save you 5%-30% on your annual utility bills (an average of $105-$627, depending on home, climate, products and use).

Furthermore, actions like proper heating and cooling equipment maintenance; turning off lights; reducing electricity use throughout your home; reducing hot water use; ensuring your home is adequately insulated; and smart use of home design elements, such as landscaping and window coverings will save you even more.

Wondering how much you could save each year with a more efficient appliance? Check out the ENERGY STAR website, which showcases products that exceed the federal minimum standards for efficiency. You can also take a look at our appliance energy use calculator to compare your current product with a more efficient one.

Also be sure to check if you are eligible for federal tax credits for energy efficiency or renewable energy. Some expire at the end of 2016, so plan your improvements now!

Finally, check out our fall and winter energy-saving tips for other ways to stay warm, save energy, and save money as the weather cools down. Happy Energy Action Month, and happy saving!

MAINTAINING YOUR AIR CONDITIONER

MAINTAINING YOUR AIR CONDITIONER

An air conditioner's filters, coils, and fins require regular maintenance for the unit to function effectively and efficiently throughout its years of service. Neglecting necessary maintenance ensures a steady decline in air conditioning performance while energy use steadily increases. Check out our Energy Saver 101 Infographic: Home Cooling for more ways to help improve your comfort and the efficiency of your air conditioner.

AIR CONDITIONER FILTERS

The most important maintenance task that will ensure the efficiency of your air conditioner is to routinely replace or clean its filters. Clogged, dirty filters block normal airflow and reduce a system's efficiency significantly. With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity. Replacing a dirty, clogged filter with a clean one can lower your air conditioner's energy consumption by 5% to 15%.

For central air conditioners, filters are generally located somewhere along the return duct's length. Common filter locations are in walls, ceilings, furnaces, or in the air conditioner itself. Room air conditioners have a filter mounted in the grill that faces into the room.

Some types of filters are reusable; others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house.

AIR CONDITIONER COILS

The air conditioner's evaporator coil and condenser coil collect dirt over their months and years of service. A clean filter prevents the evaporator coil from soiling quickly. In time, however, the evaporator coil will still collect dirt. This dirt reduces airflow and insulates the coil, reducing its ability to absorb heat. To avoid this problem, check your evaporator coil every year and clean it as necessary.

Outdoor condenser coils can also become very dirty if the outdoor environment is dusty or if there is foliage nearby. You can easily see the condenser coil and notice if dirt is collecting on its fins.

You should minimize dirt and debris near the condenser unit. Your dryer vents, falling leaves, and lawn mower are all potential sources of dirt and debris. Cleaning the area around the coil, removing any debris, and trimming foliage back at least 2 feet (0.6 meters) allow for adequate airflow around the condenser.

COIL FINS

The aluminum fins on evaporator and condenser coils are easily bent and can block airflow through the coil. Air conditioning wholesalers sell a tool called a "fin comb" that will comb these fins back into nearly original condition.

CONDENSATE DRAINS

Occasionally pass a stiff wire through the unit's drain channels. Clogged drain channels prevent a unit from reducing humidity, and the resulting excess moisture may discolor walls or carpet.

WINDOW SEALS FOR ROOM AIR CONDITIONERS

At the start of each cooling season, inspect the seal between the air conditioner and the window frame to ensure it makes contact with the unit's metal case. Moisture can damage this seal, allowing cool air to escape from your house.

PREPARING FOR WINTER

In the winter, either cover your room air conditioner or remove and store it. Covering the outdoor unit of a central air conditioner will protect the unit from winter weather and debris.

HIRING A PROFESSIONAL

When your air conditioner needs more than regular maintenance, hire a professional service technician. A well-trained technician will find and fix problems in your air conditioning system.

The technician should:

• Check for correct amount of refrigerant
• Test for refrigerant leaks using a leak detector
• Capture any refrigerant that must be evacuated from the system, instead of illegally releasing it to the atmosphere
• Check for and seal duct leakage in central systems
• Measure airflow through the evaporator coil
• Verify the correct electric control sequence and make sure that the heating system and cooling system cannot operate simultaneously
• Inspect electric terminals, clean and tighten connections, and apply a non-conductive coating if necessary
• Oil motors and check belts for tightness and wear
• Check the accuracy of the thermostat.

How to build Arduino robots complete step by step

Arduino robots 

I recommend reading through all of the instructions before you start, as that will make some things clear that might be confusing on the first time through. Also, this may look like a very long, advanced project due to the length of the instructions, but it’s actually pretty simple. No need to be intimidated – this is a beginner level project that you can get some satisfying results with, then build upon as you learn more. Don’t like this style of robot? Here’s some more Arduino robots you could easily build instead.
Here’s what we have, after taking everything out of the packaging:



To get started, we’ll attach the motors and the H bridge (the card that delivers power to the motors) to the lower part of the chassis. First, attach the four metal brackets (they’re rectangular, drilled blocks of metal) to each motor using two long bolts and two nuts.


You’ll need to make sure that they’re attached correctly, so check out the image below to make sure that the side of the block with two drilled holes will face downward. Note that the wires on each motor are pointing toward the center of the chassis.


Now each motor can be attached to the chassis by using two short bolts in the bottom of each metal bracket. Here’s a view of the bottom of the chassis so you can see where the bolts need to be:


The next step is to secure the H bridge (that’s the red board, in my kit) to the chassis. You may want to wait until all of the wires are attached to the H bridge before doing this, but that’s up to you (I found it to be easier). A quick note: my kit was missing a number of fasteners, so I used electrical tape to secure the bridge. However, you can see here where the bolts and nuts would have gone


Now that the H bridge has been attached, you can start wiring up the power supply. Because the six-AA battery holder comes with a DC adapter, you’ll need to either cut off the end (which I did) or run jumper wires to the batteries themselves.

No matter how you decide to do it, you’ll run the positive wire to the port labelled “VMS” and the negative wire to the one labelled “GND” on the bridge. Screw down the fasteners and make sure they’re secure. Then, you’ll connect the motor wires. On both sides, there’s a set of two ports; one is labelled “MOTORA” and the other “MOTORB.” Both red wires on each side will go into the centermost green port, and both black wires will go into the outermost. This picture should make it more clear


I found that I had to strip some of the housing off of the motor wires to get this to work. Now that you have the motors and the power supply all wired up, slide the wheels onto the motor drive shafts, and attach the four copper shafts in the locations show in the picture below (each copper shaft needs one small bolt). This robot is starting to take shape!


Now, set that part of the chassis aside and grab the other one which will sit on top. The next step is to attach the Arduino—again, I had to use electrical tape, but you should be able to better secure yours with some bolts and nuts.


The next step requires the micro servo, the black crosspiece, the servo holder (which consists of three black plastic pieces), and some small screws. Use one of the larger sharp screws in the kit to attach the black crosspiece to the micro servo


Then flip the servo upside down into the black plastic ring of the holder. Make sure that the wires coming out of the servo are facing in the same direction as the longer part of the holder (again, see the image below), and use four tiny screws to secure the crossbar (there are four holes in the holder that align with the holes on the crossbar).


Finally, take the other two pieces of the servo holder and snap them onto the servo (there are grooves in the side pieces that match the plastic tab on the servo


Now that the servo holder is complete, it can be mounted to the chassis.


Here’s where the bolts go:



It’s time to give our robot some eyes. Attach the ultrasonic sensor to the servo holder using two zip ties.


If you’re working from the same kit as I am, you’ll have received an Arduino sensor shield. We won’t be using it in this build, but you can pop it on top of the UNO now if you want (as I have in the image below). Just align the pins on the bottom of the shield with the I/O ports on the Arduino and press down to connect them. You don’t need it at the moment, but shields can come in handy

Whether you connect a sensor shield or not, you’ll now need four wires to connect the ultrasonic sensor to the Arduino. There are four pins on the sensor, VCC, GND, TRIG, and ECHO. Connect VCC to the 5V pin on the Arduino, GND to GND, and TRIG and ECHO to I/O pins 12 and 13.

Now grab the lower part of the chassis, and connect six jumper wires to the I/O pins of the H bridge (they’re marked ENA, IN1, IN2, IN3, IN4, and ENB). Take note of which color wires are connected to which ports, as you’ll need to know later.

Now it’s time to start putting this thing together. Grab the upper part of the chassis and set it on top of the copper shafts connected to the lower part, and pull the wires attached to the H bridge through the hole in the center of the chassis. Connect the six wires to I/O ports as follows:

• ENA to I/O port 11
• ENB to I/O port 10
• A1 to I/O port 5
• A2 to I/O port 6
• B1 to I/O port 4
• B2 to I/O port 3

Now, use four short screws to attach the upper part of the chassis to the copper shafts. Set the six-AA battery holder on top of the chassis (screw it down if you can), attach the 9V cell holder to the Arduino, and this bot is ready to rock!

Well, almost ready to rock. It doesn’t have quite enough personality yet.

There we go. Now to give it a brain. Let’s do some programming.

The first thing we’ll do is test to make sure that the bridge and motors are hooked up correctly. Here’s a quick sketch that will tell the bot to drive forward for half a second, drive backward for half a second, then turn left and right:

That’s a lot of code for a simple test, but defining all of those functions makes it easier to tweak later. (Big thanks to Billwaa for his blog post on using the H-bridge for defining these functions.) If something went wrong, check all of your connections and that the wires are connected to the correct pins. If everything worked, it’s time to move onto the sensor test. To use the ultrasonic sensor, you’ll want to download the NewPing library, and then use Sketch > Include Library > Add .ZIP Library… to load the library.

Make sure that you see the include statement at the top of your sketch; if you don’t, hit Sketch > Include Library > NewPing. Once you’ve done that, load up the following sketch:

Upload the sketch, and open up the serial monitor using Tools > Serial Monitor. You should see a rapidly updating sequence of numbers. Hold your hand in front of the sensor and see if that number changes. Move your hand in and out, and you should get a measurement of how far away your hand is from the sensor.

If everything worked correctly, it’s time to put it all together and let this thing run! Here’s the code for the robot now. As you can probably tell, this is basically the two test sketches put together with an added if statement to control the robot’s behavior. We’ve given it a very simple obstacle-avoidance behavior: if it detects something less than four inches away, it will backup, turn left, and start moving again. Here’s a video of the bot in action.

Give Your Robot Some Life

Once you’ve gotten this behavior working correctly, you can add more complex behavior; make the robot alternate between turning left and right, or choose randomly; sound a buzzer if it gets close to something; just turn, instead of backing up; you’re really only limited by your imagination. You could use just about anything in your Arduino starter kit to add more functionality. You’ll notice also that we haven’t coded anything for the servo yet: you can actually makes your robot’s “eyes” move back and forth. perhaps using them to seek out a path instead of just backing up whenever it finds an obstacle directly in front.

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Real Robots Made From Everyday Stuff

 Real Robots Made From Everyday Stuff

THE POPULAR IMAGE of robotics research involves big budgets, state-of-the-art technology and the latest materials. But in fact, a lot of cutting-edge research is done on the cheap, using things you probably have around the house. Coming up with ways to build simple, inexpensive prototypes makes it possible for researchers try lots of variations quickly and easily. Once perfected, these designs can be applied to more complex machines – although some researchers are looking into low-tech robots as an end in themselves!

Having spent the last year working on a kids’ book of simple robotics projects, I’ve been fascinated to discover how many robotics innovators are using everyday crafts materials and basic components in their work. When I started, I despaired of finding “cardboard-and-duct tape” type projects that kids would still find impressive. Boy, was I wrong! With just a little tweaking and substitution, I was able to adapt many of these real experimental robots into projects kids can readily do at home.

Here are a few I found particularly inspiring:

1. The Coffee Balloon Gripper

Most robot grippers look like hands. The prototype for the Universal Jamming Gripper developed by Cornell University, the University of Chicago, and the iRobot Corporation was different: a latex party balloon filled with ground coffee. The gripper works on the principle of “jamming” – when rough grains of material such as sand are loose, they flow like liquid, but when jammed tightly together, they behave like one solid mass. The Universal Jamming Gripper switches between one state and the other by means of a vacuum. To pick up an object, the gripper is pressed down onto it. The vacuum is turned on and sucks the air out of the balloon, packing the coffee grounds together tightly around the object. To release it, the vacuum is turned off and air is let back into the balloon. In tests, the Universal Jamming Gripper was strong enough to lift two large jugs of water, and flexible enough to pick up a penny lying flat on the table. Recent tests found that letting the air back in forcefully allowed the Gripper to actually “throw” an object with great accuracy. Inspired by Carlos Asmat, I included a homemade version in the book where the vacuum is created by sucking through a straw.

2. DASH, the Paper Robotic Cockroach

At the University of California at Berkeley in 2008, researchers designed a tiny six-legged robot called DASH(Dynamic Autonomous Sprawled Hexapod) that could scamper across the floor as quick as a cockroach. In order to be lightweight yet strong, the prototype for DASH was made out of folded, laser-cut poster board. Researchers discovered that the flexible cardboard actually gave DASH the ability to survive drops from the top of a building. But it also let researchers go from design to finished product in about an hour. Altogether UC graduate student Paul Birkmeyer spent about $50 on materials, including a small DC motor to power DASH to impressive speeds of 15 body-lengths per second. (Thanks to Birkmeyer for correcting the identification of the robots below. They are two different-sized versions of RoACH, a lab-mate of DASH.)

3. The Tinkertoy Robotic Walker

At Cornell University in New York in 1998, engineer Andy Ruina built a set of walking robot legs out of wooden Tinkertoys. Ruina was doing research into designs for a passive dynamic walker, a gravity-powered mechanism that doesn’t need a motor or control of any kind. Passive dynamic walkers don’t just save energy, they actually look more natural – sometimes eerily so. For my book I was able to simplify Ruina’s already-simple materials even further. My Mini Robot Walker, which I’ve been sharing with kids at workshops this summer, uses folded card stock, bamboo skewers, peel-and-stick craft foam and wooden beads. Here’s one from a recent workshop at the Schenectady Museum:

4. Bicycle Tube Inflatable Robots

Engineer Saul Griffith of Otherlab in San Francisco designs inflatable robots called Pneubots that look like giant blow-up beach toys. Griffith built the first prototype out of a rubber bicycle tube for $5. Later models were made of thin fabric. They included an almost-life-sized elephant, dinosaur and octopus. His six-legged Ant-Roach is a cross between an anteater and a cockroach. It’s big and strong enough to hold two adults on its back as it walks along, but light enough for one person to carry. According to Griffith, the playful creations are really serious research projects. He sees the low cost and lightweight, yet safe and strong robotic designs being used for artificial limbs or walkers. The Otherlab project Howtoons, the popular comic pages that illustrate DIY projects for kids, shows you how to make wearable pneumatic muscles using the same principles.