The smart phone has transformed how consumers expect to interact with products across markets, from automobile consoles to automated ordering systems at fast food restaurants.

The same transformation impacts home appliance displays and interfaces. Engineers have improved the functionality and design of digital displays substantially since the first smart fridge debuted in 2000 with a price tag equal to a sedan. Even as costs have come down and functionality has improved, appliance makers still battle with the reality that consumer technology often becomes obsolete at a much faster rate than the expected lifetime of durable white goods.

There’s also the simple cost arithmetic. If a smart phone costs $1,000, and consumers expect an entire oven to start at about $600, how do you square the two, especially when phones are sold at a much larger scale and frequency than major appliances?

Despite these challenges, appliances’ displays and interfaces are increasingly reflecting the phone and tablets that provide the presiding metaphor for human-device interaction. It just often takes longer for smart phone technologies to work their way down to commercial products like appliances, says Ken Soliva, director of interaction design at Design Concepts Inc. But, he says his appliance-maker clients are increasingly requesting smart phone-like elements.

“A good example of that might be the recent change that Apple has made. Previously iPhone models had a physical button for the home button, and they’ve moved to kind of virtualizing that button on the touch screen,” he says. “I’ve seen our clients want to do that with appliances. So, even if there’s not a full capacitive touch screen for a display, they’re interested in having capacitive touch buttons. It presents a sleeker industrial design and overall appearance of the appliance.”

Immersion’s demo of next-generation haptics for AR, “the Ring,” goes beyond vibration, allowing one to touch objects in mid-air. Source: Immersion Corp.

For many of the newest high-end appliances, this means controls are hidden and invisible when the appliance is off. “Whether it’s small kitchen appliances or larger-scale commercial appliances, they want the device to look really clean and like it has a simplified interface and interaction,” he says.

For a variety of reasons, Soliva sees many hybrid approaches – a mix of both digital and mechanical buttons, along with soft keys that physically exist as a mechanical control, but with function defined by software. Sometimes soft keys “provide the best of both worlds,” he says. “You have a physical tactile control that you can locate by feel; you can push and know that it responded to your interaction. But the function that it performs is going to be executed via software and can be dynamic or contextual based on what it is you are doing at that time.”

Implementing touch technology in haptic hardware components (such as actuators and ICs) creates compelling touch experiences. Source: Immersion Corp.

An entire separate article could also be devoted to voice controls, which might play out in the battle ground between Alexa and Siri. Conversely, appliance makers could also be wary of handing voice controls over to a proprietary platform such as Amazon, Apple, or Google, which would expose a device’s longevity to the whims of a company’s support and commitment to a particular voice assistant. Long-term serviceability is not unique to voice controls, and is another challenge to the integration of smart displays into appliances.

“Sometimes our clients are reluctant to adopt a technology ... because they need to think about servicing that product for 10, 15, or 20 years,” Soliva says. “They need to know that technology will be around.

There are appliances that fall in line with people’s product life expectation for their smart phone, he adds. “If I’m getting a small kitchen appliance, maybe a coffee maker, I might not expect that to last as long as my range.”

Haptics

As appliance makers replace hardware controls with touch screens, haptics play an important role in making the digital interface as intuitive and comfortable as the discarded mechanical buttons and knobs.

Haptics create tactile feedback for the user by using small actuators that create vibrating effects. These vibrations can create the illusion of pressing an actual button. The newest high-definition actuators can create micro-vibrations to convince a person that their finger has actually moved through space in the way that it would to compress a physical button, explains David Birnbaum, Immersion Corp.’s design director. This improves upon early haptics, which provided mere confirmation of a task with a limited frequency range of buzzing or vibrating effects.

“In a lab setting now, you should be able to bring a person in off the street and show them a mechanical button and a haptic button, and if they don’t know which is which, they will feel no difference, zero,” Birnbaum says. “Now you don’t need to be metaphorical with your haptics, and you don’t need to ask the user to learn anything new or accept anything new as a part of the experience.”

Even the limited haptic ability of the recent past was an improvement on early smart phones, when touching a button or key on the glass display provided no haptic feedback. Users were willing to trade tactile feeling for the performance of the software and display.

“They were like ‘Well, I don’t have physical buttons, it’s harder to type, I’m slower, but it’s worthwhile because now I can have a full-screen app, and a beautiful touch screen,’” he says. “Many things were lost when we traded that off. One is just the ability to control the device, the competence level that you have with the control. Your ability to know the action you intended took place. I think when people first started using touch screens on mobile phones, there was a lot of discussion and pushback in the press over how ‘this isn’t good enough, it’s a poor experience.’ Again, that trade-off turned out to be worth it. Then we forgot that it was a trade-off. But now we can actually improve the user experience again by introducing haptics.”

For appliances, haptic feedback will enhance the digital buttons replacing their physical counterparts.

“Now you can program the button so you don’t have to stick to one function,” he explains. “But even better than that, you can even program the haptics. So now instead of committing to the way that a button feels at build time, you can define that in software. You can make it feel different depending on what it’s doing. So now that flexibility that touch screens brought to the visual experience of devices, that’s going to be brought to the touch screen experience as well.”