Designing the future of household appliances: how advanced interfaces are modelling the user experience.
Pushbuttons and dials are increasingly a thing of the past, the future of household appliances is intuitive, interactive and more connected than ever. Driven by consumers’ expectations, cutting-edge user interfaces aim at mirroring the user-friendliness of smartphones and of the Home Assistant; the latter acts as central control hub of the smart home combining various devices and services and integrating them in a single entity.
Home Assistant is a free open-source software for the domestic automation. It is designed to be an integration platform of IoT and a central control system for smart household devices.
Innovative user experiences are becoming the rule in the household appliance sector. Precisely as consumers are accustomed to managing the daily communication with the simple touch of a finger, they increasingly expect to have similar scenarios from their hobs, dishwashers and dryers. However, while smartphones must be simply resistant for the daily use, many household appliances are called to withstand much more extreme conditions, such as high temperatures, wetness and fast vibrations. These requirements are driving the development of forefront user interfaces, with particular focus on practicality, efficiency and safety.
While R&D engineers and designers feed consumers’ growing demands with tangible products, a problem that is emerging is how developing the advanced technology required in a user interface to exceed expectations without endangering performances and reliability.
To hit innovative targets, designers must take into account a certain variety of options that lead to the implementation of touch interfaces. It is worth considering that cutting-edge interfaces in household appliances are no longer the symbol of luxury devices: they are an expectation at all levels. The different mechanisms of touch interface can be found in common household appliances, from microwave ovens to washing machines, from dryers to refrigerators. The choice of a touchscreen option instead of another depends on the wished design of the device and on the user experience we are going to satisfy, as well as on the development and manufacturing cost of functions.
The control in one touch
Although advanced user interfaces enable new interaction paths with household appliances, their design and implementation go beyond the mere functions. Besides providing innovative operational modalities, these interfaces must be safe, user friendly and reliable for an integration into the real world.
Witness of the precocious innovation in household appliances’ user interfaces, membrane switches offer simplicity, duration and convenience. Depending on the design, these switches consist of various layers; in general, as a whole, the spacer, the circuit and the laminated adhesive layers are included in the printed design. By pressing a membrane switch, you close an electric circuit that operates a control. Being one of the simplest components of the user interface in the household appliance, the layer structure of membrane switches limits both the implementation of complex functions and advanced aesthetics.
Often, in combination with membrane switches, metal domes provide satisfactory tactile feedback through a distinct sound when they are pressed. Their stainless-steel structure assures both duration and reliability, making them a convenient option for designs that try improving the user experience while maintaining a discreet footprint.
The use of the capacitive touch is a further opportunity. While membrane switches are based on the physical pressure, the touch capacitive technology uses the principle of the electronic condenser. When a user touches the screen with the finger, a variation of surface capacity occurs and it is interpretated by underlying sensors like a tactile event. Designers must consider challenges such as the implementation of specialized controllers to interpret the position and the pressure of the touch (fortuitous or voluntary), as well as the sensitivity to electromagnetic interferences (EMI).
Further improving the user experience, the touch feedback uses actuators to provide non-visual feedback under the form of vibrations or of other touch sensations. The touch feedback improves the experience confirming the user’s occurred input, providing error warnings and updates on progresses, for instance using different vibration models. Even if the touch feedback offers an involving experience, designers must attentively select the right actuator for the specific application and position it strategically close to the interaction point.
Beyond the physical interface
Advanced user interfaces on household appliances are not limited to touch options. Control and communication functions, which leave hands free, are living a growing adoption in household appliances for a comfortable accessibility and an intuitive experience, laying the bases for the next generation of devices, such as for instance the vocal control.
Using the controls in natural language, the vocal control allows users to interact with their own household appliances to start functions, like the preheating of an oven at a specific temperature and for a preset time. However, to assure a smooth user experience, designers must attentively consider various factors. To acquire vocal controls with precision, even in noisy environments, the microphone positioning is fundamental. Concerning this, the integration of the noise cancellation technology further improves the processing precision, filtering out unwanted background sounds. Moreover, designers need to integrate sound processing functions of the natural language, for instance through the artificial intelligence, to interpret user’s controls and to answer consequently.
Like for the vocal control, the gesture control offers a further hands-free control mode, using the body’s motions for controls. Although the gesture control is still in the early phases for applications concerning household appliances, it promises improving the user experience by supporting multitasking, contributing in minimizing the diffusion of germs and providing accessibility to people with physical limitations.
An efficacious gesture control needs an in-depth intentionality study already in design phase. The selection of the sensor (for instance, infrared or radar) is fundamental for the range, the accuracy and interference levels.
Facing these factors can aid the gesture control in becoming an intuitive user-friendly modality to interact with household appliances.
Sensors and processing units in household appliances commonly use sounds to provide information to users. No matter whether an error warning from a dishwasher or an update about the operational state of the oven are at stake, auditory signals are a precious aspect of the user experience with household appliances. Even if auditory signals are an efficacious manner to communicate information, designers should consider the volume, times and clarity to avoid imposing noisy unnecessary distractions in the domestic environment.
For a reliable connection
Introducing more electronic components in household appliances needs miniaturized components that must be as sturdy as their bigger-size counterparts. Connectors constitute an excellent example because they need resistance to the particular conditions existing inside a household appliance. This includes liquids, both hot and cold temperatures and vibrations. The careful selection and design of the connector’s material assure they maintain reliability in the long-term.
Therefore, all that becomes part of a household appliance must comply with precise safety regulations, from the control electronics to sensors and actuators, from internal connections to the power supply cable. For this reason, several tests are generally carried out, concerning the electric safety and reliability of the various components when subjected to stress.
The glow wire test simulates the potential fire risks, exposing household appliance components to a high-temperature element. This test uses a nichrome wire made incandescent by the passage of electric current. A test component is exposed for a specific time lapse to assess two crucial factors: its flammability resistance and the potential fire diffusion that might derive from it. This test method is particularly important for unmanned appliances, such as ovens and toasters, as well as for components where a high current is in transit, such as power supply cables and especially connectors.
Besides supporting safety requisites, the connector design plays a key role in the ergonomic assembly of appliances. When design engineers give priority to ergonomic features, such as the low coupling force, the attentively studied design of the housing and the properly defined insertion points, manufacturers can maximize workers’ efficiency, minimizing the physical fatigue.
Emphasizing the ergonomic design of connectors is an advantageous solution for all and it decreases manufacturing costs for producers, it creates a safer work environment for workers and improve the reliability for consumers. The connectors safely coupled are more resistant to vibrations and to the input of undesired substances and aid in preventing failure risks (with repairs under warranty).
