The Reinvention of the Microwave

Billy Sisson, Matt Zanchelli, and Peter Hajas

A Brief History of the Culinary Arts

Human Beings have been cooking food for a very long time. Before the advent of cooking, roughly five hundred thousand years ago, we relied on raw food to survive- mostly plant matter and some raw red meats. Such a strategy came with its own set of risks- ancient humans would subject themselves to the “taste test” to determine the safety of food.

While the origins of the first cooked meal are dubious, the benefits of cooked food over raw food are well known. Cooking food makes it safer to eat, releases more digestible and useful nutrients, and creates different tastes. Cooking created opportunities to eat foods that were never before edible; it created an almost alchemic transmutation between poisonous food to nutritionally beneficial meals. Due to the health advantages, Cooking is largely attributed to the metamorphosis of humanity from a animalistic race to a civilized one.

For the majority of the history of food preparation, an open fire was involved. Common meals were cooked in minor variations of a “large kettle over a fire” setup- the nomadic native americans had an interesting variation where heated stones were added to the water as a heat source. The concept of an “oven” began as an attempt to control the open flames used for roasting foods. Early ovens were as simple as a hole dug into the ground containing the ingredient and a controlled fire. More established societies created ovens that paralleled the traditional “brick oven” setup, using stones to cover the flame and a chimney to extract the noxious fumes.

Introduction of the Appliance

The tools of cooking did not change much over the majority of human history, since the open fire and oven provided what was needed. Around 400 years ago, the metalworking and machining processes had been refined enough to create the first cast iron stove- arguably the first appliance. The first successful Iron stove was the design of Stewart Oberlin in 1834. This stove was small enough to fit into a household kitchen, and allowed for precise control of heating and cooking durations that previous technology did not offer.

Further advancements in oven technology led to devices that did not need wood to operate. Coal and kerosene stoves became popular in the late 1800s, and gas stoves in the early 1900s. These stoves provided even more control and ease of use over their cast iron predecessors, and helped in a large part in making cooking efficient and accessible.

The advent of the electronic age led to the introduction of the electric ovens, which became popular in the mid 1900s. These ovens were revolutionary- the first large scale cooking device that did not require an open flame or combustable fuels for operation. Electric ovens also had the technical advantage of automatic temperature control as they became more advanced, further increasing the accessibility of the devices.

Advent of the Microwave

In 1945, Dr. Percey Spencer of an American Radar company called raytheon was working on building magnetrons for radar broadcasters. A magnetron is a peculiar device which was found to convert high-voltage electric current into microwave radiation at a relatively high efficiency. Spencer left a magnetron running after a test, and the Mr. Goodbar in his pocket experienced firsthand the dielectric heating effect. Percey Spencer had stumbled upon the first microwave oven.

Shortly after the discovery of this application of a magnetron, Spencer commenced testing. The first food item deliberately cooked in the microwave was popcorn, followed shortly by an egg which promptly exploded in a test engineer’s face. This microwave technology could be used to heat food in an entirely new way- directly at the molecular level. Foods with tight cooking tolerances such as chocolates and solid fats could now be rapidly heated in a microwave. The efficiency of the magnetron coupled with the speed of cooking makes microwaves the absolute most efficient way to reheat foods.

Since the introduction of the first commercially successful microwaves in the 1970s, the technology has remained very stagnant. Manufacturers have drifted from the concept of “cook for this time at this temperature” to single-button solutions for many foods. The modern microwave interface has grown complicated and cumbersome, with around 50 buttons that have very limited use cases. The technology that was supposed to make cooking easier has instead introduced an unnecessary complexity and entry barrier.

There has to be a Better Way

Looking at modern cooking appliances yields a shocking conclusion. Ultimately, the user’s goal is to cook food. Modern appliances - especially microwaves - shower the user with difficult options, many of which don’t function as expected. Several food manufacturers, like popcorn companies, encourage the user the not use the “popcorn button”. What’s the sense of having a button that doesn’t do anything you expect it to? The current swath of feature-one-upping microwaves is a sign of hostility against the consumer.

Our goal was to design a microwave which helps you cook food; not something you have to fight to coax out proper behavior. Instead of designing our microwave around some marketing feature checklist, we designed it around cooking.

Magnetron technology, the radiation and related circuitry inside of a microwave, imposed several design constraints for our re-imagined appliance. First, we need a vertically mounted magnetron on one side of the cooking area (much like a conventional microwave - most have the magnetron on the right). Next, we need a rotating plate. While earlier microwaves opted to not include the rotating surface, rotating food while it’s cooked leads to cooking the food more thoroughly.

With these design constraints, we moved forward with our design. We wanted to focus on four main areas: attractive appearance, ease of maintenance, effortless use and accessibility.

Attractive

When designing the physical appearance of the microwave, we began with a simple conclusion: a microwave doesn’t have to be ugly. Most families spend the majority of their time in the kitchen, so we should avoid having the mental weight of a hideous microwave in the most frequented room of a house. A microwave, as with all things someone owns, should be something to be proud of having. Its physical appearance should be aesthetically pleasing and interesting, but not assertive.

With this information, we moved forward with our initial design:

microwave concept

Easy to Maintain

Kitchens are messy places. Frequently, when preparing food, your hands may be dirty, which makes frequent cleaning of cooking surfaces essential for cleanliness and sanitation. Just like a countertop, a microwave should be easy to clean.

Traditional microwaves make cleaning an arduous process. They have metal seams in them, where parts of the aluminum chassis have been fastened to other internal structural parts, creating places for food to be trapped during use or less-than-careful cleaning.

Additionally, traditional microwaves utilize a rotating glass plate. This glass plate sets into a rotating piece on the floor of the microwave. This entire mechanism is clunky, irritating to clean and maintain, quickly becomes dirty, and easy to accidentally realign. We need something better.

We designed a microwave with no internal seams or lips on its design. Instead of utilizing just raw aluminum for the enclosure, we have a design that is later coated in smooth ceramic. Furthermore, our microwave has no harsh right corners internally. It’s a smooth surface, allowing for a sponge or paper towel to clean without interruption.

internal concept

Solving the rotating plate maintenance problem was more difficult. We considered several options before coming up with the idea of a magnetically aligning plate. This solves two major irritations with the rotating plate. First, the plate is simple to clean - the user can remove the plate without needing to concern themselves with the mechanism used for fastening. It’s impossible for food to become stuck in the mechanism as the rotating magnets are contained inside the chassis, separate from the cooking area. This rotating magnetic plate also solves the problem of alignment. Instead of struggling with a small plastic piece on which to align the rotating plate, magnets help it automatically align. The user sets the magnetic plate inside the microwave, and it aligns instantly. No clunking around with irritating and fragile glass parts.

magnetic plate sketch

Effortless to Use

We wanted to create a microwave that made cooking effortless. Traditional microwaves impose way too many options on the user, and complicate cooking. They frequently have difficult to set timers (many microwaves default to microwaving food for n minutes, where n is the number you press on the keypad), far too many “preset” cooking options for any regular individual, and a cluttered control surface that makes input cumbersome.

We ditched these legacy features, and looked at emerging technologies for the solution to control. In the majority of situations, a microwave should know what you’re cooking. It should be connected to the internet. Recent advances in computer vision have allowed for object detection at any rotation and scale (through feature descriptors such as SIFT) with alarming accuracy. Also, an overwhelming majority of microwavable food products feature barcodes, which can be easily read by a camera. Combining these technologies and a central food database, our microwave can scan the food you’ve placed in it, and in many situations start cooking immediately. This negates the need for the user to set the timer on the majority of microwave-prepared foods.

Microwaves are still used for their original purpose: reheating already prepared food. While our microwave won’t be able to query a central database for the best way to cook grandma’s meatloaf, it can make setting a timer much easier than current methods. Instead of having a keypad to set the cooking time, we opted to include a large, multi-touch capacitive touchscreen on the front of the microwave. A user can set this like an egg timer - simply swiping to the desired cook time radially - and do so nearly instantly.

Accessibile

Microwaves make cooking accessible to more people, but we though it would be great if they could make cooking accessible to nearly all people. Some people have physical disabilities such as Parkinson’s which prohibit fine motor control, and can make cooking a frustrating process. Other individuals have mental conditions that make cooking difficult (if not impossible) due to impairments in memory and timekeeping. These conditions often mean that someone has to enter assisted living, or have someone like a family member assist them in preparation of their food. This can be heartbreaking for the family, but also for the individual, feeling as though they’ve lost their independence.

If these people could have an appliance that let them have prepared food without needing to enter assisted living, that would make a remarkable improvement to their quality of life.

Our microwave has a large button to open the door, far larger than traditional microwaves. It also takes far less effort to open our microwave door. This allows users with physical disabilities, including the elderly, to open and close our microwave with very little force and precision required.

Because the microwave is internet protocol aware, it can be remotely configured to turn on or cook food at a specified time. This has staggeringly large implications. Someone lacking fine motor control can have their microwave configured to reheat food by a family member, removing the need for them to set it themselves. If they’re preparing microwavable food, then they need not set the microwave at all - it can read the detect the food the user’s cooking, and automatically cook it.

For users with mental conditions, an internet-aware microwave can provide additional help. It can remotely tell family members how their cooking habits are progressing, alerting early if someone’s not eating. It can be remotely configured to remind someone to eat various times throughout the day, prompting for the food to be inserted. This allows individuals with memory impairment to keep a schedule of food in their lives, and gain an alarming amount of independence.

Simple steps in the design of an appliance can have profound effect on how accessible it is.

Examining our Design

First, the reasoning behind our decisions are explained. Then, to verify our proposed design, we’ll consult some of the guidelines suggested by successful designers and human factors specialists.

Our Proposed Design

A Clean Interface

Our Proposed Design

Our microwave will feature a very clean interface. It only displays what it needs and nothing more. By creating such a clean interface, there are fewer distractions than your typical modern day microwave. Fewer distractions means less confusion for our users. With less confusion, the user can get started microwaving even sooner. After all, the whole point of a microwave is to cook something quickly— let’s help our users get right to the point.

Should the user want the current time displayed on the face of their microwave, only a small switch is necessary. Now the screen on the face of the microwave displays the current time in large, readable text in the center of your kitchen.

Microwave with time

Setting the Cook Time

Perhaps the most unique part of our design, is the giant dial shown on the glass display. Like an egg timer, simply slide your finger radially around the circular display to set the cook time. The dial can also be adjusted at any point in the microwaving process.

Simply tap the front of the microwave, if necessary:

Tap

Move your finger to the edge of the dial

Set Time

Slide it down to your desired time

Set Time-2

and the microwave will start counting down and cooking:

Cooking

Cooking-2

The timer’s nearly logarithmic scale makes it easy to set the appropriate cook time:

Graph of time

This allows quick, yet precise setting of cook times. The difference between 0:30 to 1:00 and 59:30 to 1:00:00 are both 30 seconds, however the difference in the latter is much less significant. Why is this the case? Thirty seconds counts more when a cook time is only a minute as opposed to an hour cook. Thirty seconds is 50% of one minute, whereas thirty seconds is less than 1% of one hour.

By expanding the lower regions, and thereby shrinking the upper regions, we allow for greater precision when it’s necessary and less precision when it’s not.

A simple logarithmic scale would have been a sufficient solution to this problem, but we can modify it to work even better with common microwaveable foods.

We discovered that different foods fit roughly into three categories:

Chunking these types of foods together allows greater precision within each category. Since many foods often fall in one of these categories and not as much in between categories, our scale should reflect this. As seen in the above graph, there are three visible regions in the scale.

One may think that a very complicated, non-linear scale would confuse the user, but in our tests, it felt much more natural to dial on this scale as opposed to a purely logarithmic or linear scale.

Times shown on dial

The colors shown over the set time will match those shown above. The colors also follow the same scale. As the cook time increases, the color changes from yellow, to orange, to red. As the rotation increases, the brightness decreases.

In order to additionally aid users, the current cook time is shown to the right of the dial at all times.

Also aiding the quick start of our microwave is the food scanner. In most cases, the microwave will know the appropriate cook time and start as soon as the door closes. Any small adjustments to the cook time can be made while it’s cooking.

Fitts’s Law

Paul Fitts spent his life studying psychology, specifically information theory and human movement. He was the president of the American Psychological Association as well as the Human Factors Ergonomics Society. In 1954, he proposed his law which can be described as:

a model of human movement in human-computer interaction and ergonomics which predicts that the time required to rapidly move to a target area is a function of the distance to and the size of the target. Fitts’s law is used to model the act of pointing, either by physically touching an object with a hand or finger (Psychology Wiki)

Most modern microwaves feature small buttons, not much bigger than a square inch, and require you to move across the keypad (typically with one finger) pressing this small buttons. Fitts’s law, which is a function of the distance to and the size of the target, is completely disregarded by the design of the modern microwave.

Our design vastly improves on the microwave’s ergonomics, according to this law. In the case that a cook time is required to enter, the user simply needs to move their finger in the general direction of the desired time and let go. The area for a given time is much greater than a small button. Also, only one direction of movement is necessary to set a time, as opposed to the standard keypad.

In order to compare the two, we’ll pretend we need to cook something for 1:30 (one minute and thirty seconds). To set the time on a modern microwave, here is the process:

In our design, the process is much faster, according to Fitts’s Law:

Hick’s Law

William Edmund Hick was a psychologist who specialized in ergonomics. As a founder and president of the Experimental Psychology Group and founder of the Ergonomics Society, he proposed a law that describes:

the time it takes to make a decision is roughly proportional to … the entropy of the decision (the log of the number of alternatives) (Usability First)

This law suggests that the fewer choices given to the user, the faster their decision will be.

In an average microwave, there are 10-20 additional buttons (and the keypad) that the user is presented with when microwaving their food. We believe these are rarely used and highly unnecessary. We’ve removed all buttons except for one which will open the door. The user is presented with much fewer choices on the microwave with our design, which will decrease the time it takes for the user to make a decision.

Ten Principles of Good Design

Dieter Rams is a designer who is known for his outstanding work he’s done for Braun, a German consumer products company. He is famous for his question “Is my design good design?”, which led him to create the “Ten Principles of Good Design”.

To verify our design as good design according to Dieter Rams, our design will be briefly analyzed according to each of the ten principles.

  1. “Good design is innovative” We are unaware of any other microwave featuring a translucent display used to set and display cook time.
  2. “Good design makes a product useful” Our design promotes using the microwave as a way to cook food. It disregards all buttons and other useless features that may possibly detract it.
  3. “Good design is aesthetic” Our design is very much aesthetically pleasing, with it’s very minimal design and seamless and solid construction.
  4. “Good design makes a product understandable” We believe our design will appear obvious to those using it.
  5. “Good design is unobtrusive” The design is very neutral and out of the way when need be.
  6. “Good design is honest” We did not attempt to replace a conventional oven with our microwave. It’s not trying to be something it’s not. Our microwave is what it is: a microwave.
  7. “Good design is long lasting” It’s structurally sound and it’s neutral design will be timeless.
  8. “Good design is thorough, down to the last detail” The last detail is the end of this product’s life– after it stops functioning as a microwave. After many years, when the microwave stops functioning, the microwave’s rotating plate can be donated to someone in need of a plate to eat off of.
  9. “Good design is environmentally friendly” Our materials will be largely compromised of recycled material.
  10. “Good design is as little design as possible” Our microwave is certainly minimalistic:

As little design as possible

Bibliography

Psychology Wiki. May 2012. http://psychology.wikia.com/wiki/Fitts%27s_law

Usability First. May 2012. http://www.usabilityfirst.com/glossary/hicks-law/