According to MEMS Consulting, in the past decade, intelligent technology and the Internet of Things (IoT) have made remarkable progress and have had a significant impact on industry and people’s daily lives, largely thanks to the continuous development of increasingly sophisticated sensors. Today, electronic sensors and detectors have achieved unprecedented automation capabilities in fields such as automotive, manufacturing equipment, consumer products, and homes. The proliferation of mobile devices and the associated computing power, dedicated applications, and intangible connectivity are driving consumer demand for more integrated and intelligent electronic products, making various aspects of daily life more automated.
IoT is driving rapid growth in the smart home technology sector and requires smarter infrared sensor technologies to support the increasingly innovative smart home interconnectivity (Image source: Excelitas Technologies). To stimulate consumer demand, rapid innovation has brought about a new generation of smart devices that can quickly and automatically handle daily operations. With the help of continuously advancing interface technologies, these devices can enable, disable, and pre-program various functions. The more complex and automated the functions, the more electronic devices need to obtain more perceptual data from their operating environments, such as temperature, motion, and presence of people, and operate and interact based on this data. For example, air conditioning and heating systems are the most energy-consuming parts of household electricity. Smart thermostats using infrared sensors can control based on human motion and presence to save energy and maintain a comfortable temperature. Advanced HVAC systems can utilize infrared sensors to scan rooms, generate thermal maps, and control air temperature. Infrared sensors automatically activate and control thermostats by providing real-time necessary environmental information. By supplying detailed thermal information about the room, even the heat from sunlight penetrating through windows can be accounted for, allowing for accurate calculations of the room’s heating and cooling needs.
Motion detection is a key component in smart home products and systems (Image source: Excelitas Technologies). Infrared thermal sensors, with multifunctionality, ease of integration, relatively low cost, and sensitivity to human heat, are particularly suitable for human-computer interface applications. Significant advancements in infrared sensing technology help simplify system integration to meet the high competitiveness and rapid market cycles required for consumer products.
Infrared motion thermal detection is a critical component of sensor technology in intrusion alarms and home security systems (Image source: Excelitas Technologies). As product applications expand, there are many urgent needs to meet the growing perceptual demands of smart devices, including miniaturization, software-controlled flexibility, energy efficiency, enhanced sensitivity, and easy integration in product design. In many cases, these improvements can interact and promote each other. Miniaturization Consumer demands trend towards continuous iterations of more compact and convenient smart devices, meaning smaller sizes and lower presence. Therefore, as the practical performance of smart technology in home and personal devices increases, original equipment manufacturers (OEMs) are looking for ways to package more technology and functionality into smaller devices. This means that smaller sensor components and designs need to be both compact and practical, allowing smart systems to be almost invisible around us. The goal is to save space as much as possible, integrating as many devices as possible into their application environment. Compared to traditional integrated lens transistor packaging (TO packaging) designs, new packaging such as Excelitas’s SMD (Surface Mount Device) infrared thermal detectors can significantly reduce size, thereby improving spatial efficiency. SMD packaging supports machine assembly production, making it more suitable to meet the efficient production lines required by the rapidly growing consumer segment. SMD packaged sensors are smaller, allowing for more micro-sensors to fit per square millimeter, supporting increasingly compact electronic host device designs. Along with the smaller size comes the need to shrink optical systems as much as possible. Traditionally, Fresnel plastic lenses used to provide the performance required for remote detection applications are quite large. When shrinking these lenses to achieve micro-sized devices, infrared sensors must compensate with higher sensitivity. Advances and developments in proprietary sensor substrate designs are significantly enhancing sensor area, meaning increased sensitivity (e.g., faster triggering of weaker event signals) and expanded effective sensing range. Today’s latest SMD sensor designs can effectively detect events within a three-meter range without bulky magnifying glasses or windows, further enhancing spatial efficiency in host system designs. Improved Signal Processing Miniaturization, enhanced sensor flexibility, and software control capabilities promote spatial utilization and multifunctionality in smart product design. Advanced application-specific integrated circuits (ASICs) and improved digital infrared sensor technology signal processing now enable infrared sensors to monitor and detect multiple factors and distinguish between motion detection events and presence monitoring. This can simplify the ability to use various sensor points in the host system’s mesh network and relay dedicated data from different locations to the central control area of the host system. For example, in a smart home’s HVAC control system, the sensor network can activate the system from “standby” mode by detecting human entry, monitor human presence in specific activated areas, detect motion when people enter other areas of the smart home, and ultimately monitor/report the ambient temperature of the entire home, accounting for variables such as sunlight movement, nightfall, or weather fluctuations. It is this kind of network integration that will continue to drive the development of digital sensors and expand the application of infrared sensing technology in the consumer field. Extended Power Efficiency Optimizing the energy demands of sensors not only extends the lifespan of remote and mobile smart devices but also reduces device size by significantly lowering power requirements. Lithium batteries have greatly improved the mobility of devices, initially used in smartphones with small, efficient rechargeable batteries, and now in other products like electric vehicles and e-bikes. In household devices, lithium battery-powered smart products and systems are reducing the need for hardwired facilities. Light switches, phones, doorbells, and Internet Protocol (IP) cameras are just a few examples.
Excelitas’s low-power DigiPyro 1500 series sensors have been improved to operate on a 1.8-volt power supply, extending their field lifespan and reducing the power demands of smart homes and portable electronic devices, enhancing spatial economy (Image source: Excelitas Technologies). For these devices, the operational time before charging becomes an important metric. For example, IP cameras can be installed in locations that do not interfere with users’ daily charging. This allows lithium batteries to provide months or years of battery runtime. To fully leverage the low-voltage advantage for battery-powered devices, many microprocessors now support 1.8-volt operation. Low current consumption can reduce the overall power budget, enabling long-term operation. This requires the development of new sensors that “support 1.8-volt operation and require less current,” with recent breakthroughs in this technology. Higher Sensitivity An important aspect of power efficiency and performance is the ability of passive sensors to operate in “sleep” mode, requiring not only minimal energy consumption in standby mode but also a lightning-fast wake-up function to activate the host smart device. For example, for security or home monitoring cameras, this can make a significant difference in application effectiveness—such as cameras being set to “wake up” from standby mode and quickly autofocus to capture meaningful motion images within their field of view. Since devices only use full power when detecting human presence, this extends device lifespan and reduces the energy consumption required by the device. Even when devices are in sleep mode, precise sensitivity is needed to achieve the necessary wake-up and rapid activation. Typically, the applications use pyroelectric detectors and sensors. They can provide high sensitivity and high-frequency response for remote motion detection. Motion signals are transmitted directly to the microprocessor for optimal response and sensitivity, which can then be processed by software programs based on environmental conditions and settings. The pace of change in the smart product field is fast and variable. The ability of OEMs to develop and launch products in a short time significantly affects product success or failure. OEM design engineers need easily integrable sensors to achieve shorter product design cycles. Development time can be shortened by leveraging electronic devices with ready-to-use design modules, as most electronic devices today focus on digital technology, making digital technology the best option. This means a wide variety of sensors need to be digitized and capable of communicating with surrounding electronic devices. In daily life, smart devices will continue to grow and take on more roles. Battery-powered switches, IP cameras, and security lights enhance the overall safety and convenience of living and working environments while also improving energy efficiency. When connected through IoT, overall performance becomes smarter and more convenient. More importantly, environmental adaptation based on presence and motion will become a commodity. The increasing demand for more complex interactive requirements in new applications will drive the continuous development of various technologies, including the aforementioned sensor technology innovations. Sensors, especially infrared sensors, will undoubtedly continue to play a key role in the technical support of IoT and smart products.
Further Reading: “Sensors and Sensing Modules in Smart Homes and Smart Buildings”; “Temperature Sensor Market – 2016 Edition”; “Uncooled Infrared Imaging Technology and Market Trends – 2017 Edition”; “Infrared LED and Laser Technology, Applications, and Industry Trends”; “Camera Module Industry Market and Technology Trends – 2017 Edition”; “Infrared News” – Second Half of 2017 Edition
