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Rapid prototyping within the tech field, especially within the context of smartwatches and nanotechnologies, is crucial. Emerging consumer trends, such as the demand for heart rate monitoring capabilities in both digital and mechanical smartwatches, make the ability to iterate and work with advanced light sensor technology essential for rapid development. As a company rooted in high-precision engineering and Swiss excellence, ActLight seeks to revolutionize the smartwatch industry with our groundbreaking Dynamic PhotoDetector (DPD) technology. In this article, we will explore how DPD facilitates rapid smartwatch development and the work that goes on behind the scenes at ActLight.

The Crucial Role of Light Sensing in Smartwatches

Watches have evolved significantly from their origins in the 16th century as simple timekeeping devices. The transition from mechanical to digital in the late 20th century marked a major technological leap, leading to the modern era of smartwatches. Today, smartwatches are sophisticated devices that rely heavily on advanced sensors to provide a range of functionalities. Among these, light sensors play a critical role in features such as heart-rate monitoring, blood oxygen level tracking, and ambient light sensing. The accuracy and efficiency of these sensors directly impact the performance and user experience of the smartwatch. At ActLight, our investors and team believe in our vision of raising the bar for smartwatch monitoring, making it a compelling choice for forward-thinking smartwatch manufacturers

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Accelerating Development with ActLight’s DPD Technology

One of the standout advantages of ActLight’s DPD technology is its ability to facilitate rapid development cycles for smartwatch manufacturers. Our technology is designed to integrate seamlessly with existing production processes, thanks to our use of standard CMOS technology. This compatibility significantly reduces the time and cost associated with custom sensor design and fabrication.

Prototyping Made Easy: We offer a streamlined process that allows manufacturers to test and prototype our technology. This includes access to our lead engineers, who provide expert guidance and support throughout the integration process. Our team’s expertise ensures that potential challenges are addressed swiftly, enabling a smoother transition from concept to market.

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Unmatched Sensitivity and Precision

ActLight’s DPD technology is engineered to deliver exceptional sensitivity, capable of detecting even the smallest variations in light. This high sensitivity is crucial for accurate heart-rate monitoring and blood oxygen level measurements, which require precise detection of subtle changes in light intensity. By tuning our sensors to such fine levels of sensitivity, we ensure that smartwatches can provide reliable and accurate health monitoring, a key feature that consumers increasingly demand.

Our recent work at the Center of MicroNanoTechnology (CMi) focuses on further enhancing the sensitivity of our DPD sensors. By reducing internal capacitance and improving carrier collection within the device, we are pushing the boundaries of what is possible in light sensing technology. This cutting-edge research involves treating silicon wafers with epitaxial layers that have well-defined p/n doping profiles, followed by advanced back-end processing techniques at EPFL-CMi.

A close-up look at ActLight’s wafers
Treating of silicon wafers

Advanced Manufacturing Techniques

In line with the latest trends in both digital and mechanical watches seeking to integrate advanced sensor technology, our DPD sensor manufacturing process emphasizes precision and innovation. To ensure high-quality and reliable performance, we start by partnering with an external company that treats the silicon wafers to grow epitaxial layers with well-defined p/n doping profiles:

  • Aluminum Sputtering: This process is used to create metallic contacts, ensuring robust and reliable electrical connections within the sensor.
  • Plasma-Enhanced CVD: Silicon dioxide (SiO2) is grown using this technique to serve as an insulating layer, enhancing the overall performance and durability of the sensor.
  • Deep Reactive Ion Etching (DRIE): DPD sensors are shaped by etching deep trenches, which isolate the active device from the rest of the wafer, significantly improving carrier collection and reducing capacitance.

To achieve the high resolution required for some patterns, the design is translated to a mask, and lithography steps are performed using a deep ultraviolet (DUV) stepper with an optical shrink of 4x. This meticulous process ensures that our sensors are isolated on the wafer, protecting them from dust and contamination during the final dicing step. The resist is then stripped at the chip level, making the sensors ready for placement and bonding on printed circuit boards (PCBs).

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Licensing Opportunities for Swift Integration

ActLight’s DPD technology is available for licensing, providing smartwatch manufacturers with a robust, patented solution that is ready for integration. By licensing our technology, manufacturers can leverage our advanced light sensors to rapidly prototype and bring new products to market. This not only reduces development time but also minimizes costs associated with sensor design and fabrication.

Our technology’s integration into standard CMOS processes further enhances its appeal, making it cost-effective and easy to incorporate into existing manufacturing workflows. This seamless integration capability allows manufacturers to focus on innovating other aspects of the smartwatch, confident in the knowledge that their light sensing needs are met with the highest precision and reliability.

Learn more about our technology by reading our white paper

The Swiss Advantage

As a Swiss company, ActLight embodies the values of precision, reliability, and excellence that are synonymous with Swiss engineering. Our focus on continuous research and development ensures that we stay ahead of industry trends and technological advancements. This dedication to innovation is reflected in our ongoing work at CMi and our commitment to enhancing the performance of our DPD sensors.

take a look at this video explaining our work in more detail

Conclusion: Partnering for the Future

For smartwatch manufacturers looking to stay competitive and innovative, partnering with ActLight presents a unique opportunity. Our DPD technology not only meets the current demands of the smartwatch market but also positions manufacturers to capitalize on future trends and consumer expectations. By licensing our technology and utilizing our expertise, manufacturers can access state-of-the-art light sensing capabilities, reduce development cycles, and bring high-performance smartwatches to market faster.

We invite you to explore the potential of ActLight’s DPD technology and see how it can transform your next smartwatch project. Visit our applications page to learn more about our innovative solutions and how we can support your journey from concept to market.

Are you ready to reach out right away? Contact our CCO on LinkedIn, Roberto Magnifico.