As it’s difficult to be in two places at one time, I was happy to see that the organizers of the co-located European MEMS and Sensors Summit/Imaging and Sensors Summits made sure two featured tracks —the MEMS and Sensors Technology Showcase and The Imaging Sensors Start-up Pitches — did not run in parallel. As a result, I attended both. This post focuses on the MEMS and Sensors Technology Showcase.
The five finalists competing for the coveted prize: a free exhibitor booth at next year’s summit, included Bosch SensorTech’s MEMS laser micro scanner for interactive laser projection, presented by Lutz Rauscher; Phillips Innovation Services’ CMUT “breakthrough” ultrasonic technology, represented by Paul Bekkers; SiWares’s spectral sensing for ubiquitous material sensing, presented by Bassam Saadany; Fraunhofer IPMS’ MEMS-based ultrasonic systems for fluid and gas-based applications, presented by Mario Grafe; and Hap2U’s ultrasonic piezo transducers for smart haptic solutions for touch screens, presented by Matthieu Rupin. In addition to the 10-minute presentations, each presenter had a spot on the exhibitor floor for demos, and attendees queued up for a glimpse at these cool technologies in action.
MEMS Microscanners for Interactive Projection
I was captivated by Bosch’s embedded miniaturized projection solution for its elegance and simplicity (Figure 1). With it, you can turn virtually any surface into a virtual user interface for mobile computing, gaming and entertainment, or smart home control. No buttons, no touch screen – just projected laser images and creative software that allows the user to perform actions like switching a light on and off or playing a game. Additional use cases include mixed reality and user guidance for robotic applications, explained Rauscher. It also has the potential for industrial applications, but Bosch focused first on developing consumer applications.
Rauscher explained that the complete system includes video control, drivers, four lasers in one beam, and two mirrors for horizontal and vertical projection. How does it work? A focused laser beam writes images on the screen to achieve focus-free projection. Because of wafer-level encapsulation, the mirrors are hermetically sealed and retain performance throughout their lifetime. How do you get it? Rauscher said a reference design evaluation kit is now available to customers.
Capacitive Micromachined Ultrasound Transducers (CMUTS)
Both Bekkers and Grafe showcased CMUT-applications. Bekkers’ presentation focused on CMUT for medical imaging purposes to replace harmful X-ray procedures and bring affordable, premium ultrasound capabilities to handheld and wearable devices. He said other applications enabled by CMUT includes miniaturized in-body imaging, ultrasonic fingerprint scanning, corrosion management, gesture detection, haptics, and more.
As Bekkers describes it, the technology platform involves placing parallel capacitive transducers on each side of a membrane on top of the substrate (Figure 2). The CMUT allows for a huge range of actuation transmission flexibility. The pressure waves provide an output signal. What makes Philip’s Innovation Services CMUT technology breakthrough? It has a high level of integration due to CMOS back-end processing, integrated flexible interconnects, and design freedom. Bekkers says it provides premium performance, handling frequencies up to 40Mhz and 5MPA acoustic pressure. Lastly, he said it is ramp-ready due to a modular technology platform, volume manufacturing, and in-line process control, with a time to market of only a few weeks from design to the first batch. “It ticks off all the boxes of being ready for all kinds of applications,” noted Bekkers.
In his presentation focusing on CMUT for applications in a fluid environment, Grafe showcased and integration example of an air-coupled single CMUT with a CMUT ASIC destined for medical diagnostic and non-destructive test applications. This CMOS compatible MEMS/ASIC design is manufactured in a 200mm MEMS foundry and can either be integrated monolithically (MEMS on CMOS) or via heterogeneous integration using through silicon via (TSV) interconnect technology, noted Grafe. Miniaturized and scalable, the CMUT is highly sensitive and cost-efficient.
Ubiquitous Spectral Sensing
Si Ware’s entry into the technology showcase was it’s NeoSpectra MEMS spectral sensor device that enables materials analysis anywhere (Figure 3). Dubbed by Saadany as “the world’s first spectrometer on a chip,” this device takes the ability to test blood, urine, skin cells, food samples, and more outside of the lab and into the field. Integrating MEMS sensors enables the spectrometer to be small and affordable, and can be operated by individual users rather than specialists.
Designed for use in multiple industries including healthcare, agriculture, oil and gas, food processing, automotive, pharmaceutical and industrial, Saadany says this device will impact human lives in numerous ways. It can be integrated into wearables, smartphones, internet of things (IoT) devices, and embedded sensors to change the way we, for example, test for skin cancer, analyze soil samples, detect allergens in food, sort pills, and more.
What makes it so small? Si-Ware has figured out a way to integrate the MEMS sensor, self-aligned optics, photodetector and ASIC all into a system-in-package (SiP) – let’s hear it for heterogeneous integration! Saadany said the first generation of NeoSpectra has been implemented in industrial applications, and the company is now targeting consumer smartphone applications.
Haptic Touchscreens
According to Wikipedia, haptic technology recreates the sense of touch by applying forces, vibrations, or motions to the user. The final contestant in the technology showcase, Mathieu Rupin, Hap2u, talked about the new way to interact with machines that involve semiconductor-based thin-film piezoelectric transducers.
Currently, machine interfaces allow the user to interact with the machine but does not allow the machine to interact with the user. This haptic technology changes that by enabling bi-directional touch screens that allow you to feel the sensation of pushing a button, flipping a switch, twisting a dial, or turning a page. He said haptic touchscreens make it possible to remove all buttons from mobile devices, makes automotive navigation safer, and makes touchscreens more accessible to the blind.
How it works: Rupin described creating a squeeze-film effect by putting a pressurized film of air between the ultrasonic standing wave generated by piezoelectric activators and the touch screen cover glass. The piezoelectric actuators make it possible control friction modulation in real time. The vibration is synchronized with the position of the finger and makes it possible to feel the texture and apply force (figure 4).
Rupin says there are still kinks to be worked out, such as making the actuators fully transparent. The company is also working to integrate more features such as audio interaction. I tried it out in the technology showcase – yes- it felt like the fish scales were real, but the same sensation was generated when I tested the buttons and switches. For all intents and purposes, it can see the advantages of the technology, but there’s more tweaking to be done before we’ll be able to differentiate between scaley and furry textures.
And the winner of the technology showcase?
The winner of the showcase was chosen the old-fashioned way – an attendee paper ballot. It was tough to choose from such an impressive field of candidates, but no one was really surprised when the winner was announced at the Gala Dinner (FIgure 5). His presentation was captivating and interesting, and the application space for this technology was the broadest of all. The free booth for the 2018 MEMS and Sensors Summit was awarded to Bassam Saadany, Si-Ware, for the NeoSpectra Spectral Sensor. Congratulations! We’ll be on the look-out next year for gen-3 of the NeoSpectra. ~ FvT
