Engineering an IoT Appliance: The Watched Pot That Never Boils

Nise Tech’s home appliance, the Wave, is an example of a product designed with the Internet of Things (IoT). Nise took the concept of an immersion heater, made it work for sous vide (more on that in a minute), adapted it for home use—and in the process and made it smart and connected. When the Kickstarter project is complete—and if it lives up to its billing—you’ll not only be able to cook your meals from the office, you’ll also be able to give the appliance last-minute instructions. We can imagine giving the device commands like “working late, keep dinner warm,” and it will lower the temperature—smartphone to smart device.

Nise has raised almost $300,000 on Kickstarter for its Wave sous vide cooking device. (Image courtesy of Nise Tech.)

Nise aims to have its Wave device change our relationships with cooking. “The device should be like your butler, not your servant,” said Grant Hu, cofounder of Nise Tech. Grant joined up with Rayner Mendes. Grant was already involved with restaurant automation in China. Together, they want to enter the U.S. market.

Most so-called smart devices are not really that, says Grant. From your smartphone, you can only turn such devices on or off, with simple commands like what you might issue to a simple servant. Nise promises more sophistication with the Wave. Butler-like, the Wave does some thinking for you, delivering an outcome rather than simply slavishly executing your commands. Suppose you are stuck at work. Your servant at home might be able to turn off your cooking device. As a more butler-like device, the Wave will turn down the temperature and extend the cooking time so that your meal is ready when you walk through the door.

Having a smart device dedicated to cooking will also allow a rethinking of how food is cooked. The FDA relies on a single temperature as a measure of food safety: Get your cuts of meat to 145°F (63°C) and you won’t get sick.  However, heating to lower temperature for a longer cooking time can be just as safe. Besides, cooking at 145°F cooks out “6 times the moisture as a rare steak” and changes the meat to have a “cottony, grainy texture,” per seriouseats.com.

Design Challenges

Most competing products are under powered at 700 to 800 Watts, according to Grant Hu, cofounder of the Chinese Nise. This means that you have to wait around for your food to cook. Nise designed the Wave to operate at 1200 Watts. Also, the most sous vide cookers are not completely submersible. You can only submerge the tip of most immersion heaters, which make them difficult to rinse off. The trick was to get a relatively compact device with a lot of power with the convenience—and safety—of being submersible. The Nise Wave is water resistant to IP67, according to the product’s literature, which is identical to one of the latest iPhones. You can rinse the Wave off and stick it in your knife drawer, says Mendes. You cannot do that with the larger, restaurant-use sous vide devices.

Sous vide (pronounced soo-veed) is French for “under vacuum.” Bags used in sous vide can be vacuum sealed, but Ziploc bags with most of the air squeezed out of them seem to work just fine. Sous vide is a method in which food is cooked below the boiling temperature of water, at a temperature that is high enough to kill germs and cook food, but not high enough to scorch or dry it out. Sealed plastic pouches keep the food from getting waterlogged. Sous vide cooking is practiced in high-end restaurants to prepare, thaw and cook food. It is a technique that preserves most of the food’s moisture, as opposed to dry, hot processes that tend to dry out food. However, the method requires a final finishing touch for certain foods in order to avoid that unappetizing, boiled look.

The Wave is an 11-inch tall dark plastic device with touch controls—similar in shape to the big pepper grinders steak restaurants are famous for—that is water resistant, if not fully submersible.

Restaurant sous vide devices can’t be easily cleaned, and they can short circuit or electrocute the user, says Mendes.

The Wave’s pump and heating element. The mechanical design was created with SOLIDWORKS. The device’s thermal and fluid analysis was made using ANSYS and COMSOL. While water circulation can remove the heat from the coil, the device had thermal issues with heat building up in other areas, heating the trapped air in two other sections and affecting the components on the PCB. Fluid flow around the coils was predicted with thermal and CFD software in the wet section. The air-filled sections were not modeled. (Image courtesy of Nise Tech.)

While the heating technology the Wave uses is nothing new, it is the device’s attractiveness, convenience and usefulness that Nise hopes will make it a success. It is a precedent firmly established with everyone’s favorite example: the iPhone, which  revealed no earth-shattering technology but nevertheless became an unparalleled success by looking good and being cool.

Manufacturing in China offers Nise many advantages. “Everything happens faster here,” said Hu. “People work around the clock. We can give them a change in the circuit board and have a new one 11 hours later.”

Cord waterproofing that is critical to safety and consumer use. (Image courtesy of Nise Tech.)
Stacked. We put a small brain in the device, but keep the big brain on the server, say Nise Tech founders. (Image courtesy of Nise Tech.)

The Wave works best when it’s connected to the Internet but is not completely lost without it. Enough command processing happens locally on the device API server so that in the event that the connection is not available, the device still performs its basic commands—and is still a little smarter than a typical appliance. However, it’s when the device is connected to the Internet that the Wave user would reap most of its benefits. Over the connection in the remote application server is where recipes and cooking times are stored. Also, calculations to adjust cooking times are made there. On the remote server sits the device’s digital twin, interacting with commands, processing, making decisions, adjusting cooking times (to accommodate a delay,for example) and piping them back to your device. A connection to the cloud storage (Amazon Web Services, AWS) provides access to images and cooking videos. You interact with the device through an app on your Android or Apple device.

Preorders are being taken for $129.The Wave’s eventual price will jump to $199 when it’s in full production. The devices expected ship date was originally April 2018, but has been pushed out to September.