MEMS accelerometers are putting the pedal to the metal – Interview with Physical Logic

High-performance motion sensing is of paramount importance in numerous defense, commercial aerospace and naval and industrial applications. Whilst Covid-19 will have some negative impact on most of these markets, industrial promises, on the contrary, the highest compounded annual growth rate (CAGR) in the next five years, at more than 10%. That’s according to Yole Développement (Yole)’s latest report, “High-End Inertial Sensors for Defense, Aerospace and Industrial Applications 2020”.
The rise of inertial systems in industrial applications in recent years has been driven by the possibility of integrating new functionality at lower cost with good performance. MEMS is the preferred solution for this market due to the low cost, size, weight and power (C-SWaP) combination that it offers. And as MEMS performance increases, it is only logical to wonder how big a threat it will pose to legacy technologies. While MEMS gyros are lagging behind, the battle is ongoing, with MEMS accelerometers having reached navigation-grade requirements already. For a better insight, Dimitrios Damianos, Technology & market Analyst at Yole has interviewed Aviram Feingold, Chief Executive Officer of Physical Logic, to explore the latest developments of the company’s MEMS accelerometers.

High end inertial main segment value 2019-2025 market forecast

Dimitrios Damianos (DD): Physical Logic is a known high-end inertial system player. Could you briefly present your activities, products, markets and applications and your differentiation from other players?

Aviram Feingold (AF): Physical Logic is dedicated to developing and producing cutting edge MEMS based accelerometers. Our mission is to provide customers with leading, high performance accelerometers based on our MEMS technology. Our accelerometers serve various applications including inertial navigation, vibration monitoring, seismic and tilt sensing systems.
Being a relatively young company, Physical Logic is aiming to further establish itself as a leading independent MEMS accelerometer manufacturer in the marketplace.

DD: How have the last one to two years been for your high-end inertial business and what were the main drivers and highlights?

AF: The past few years were very exciting for us since the market has been picking up on our technology and we are involved in a lot of challenging and important projects. During this period Physical Logic has established collaborative relations with some of the leading producers of advanced Inertial Measurement Units (IMUs) and Inertial Navigation Systems (INSs). In this regard, we have been acknowledged as an inertial-grade MEMS accelerometer supplier for national and international defense companies.

Internally, we are ramping up our facility for mass production. Based on our cutting-edge equipment, our highly trained production team, together with well-qualified subcontractors, we are capable to assure manufacturing efficiency and product reliability for all our customers.
It is important to mention that all Physical Logic’s activities fully comply with AS9100D and ISO9001-2015.

DD: A few years back Physical Logic released its closed loop accelerometers. What are their strengths, for example transducer design and Application-Specific Integrated Circuit (ASIC) technology?

AF: As you are aware, lately we have announced the release of our Inertial Grade Closed Loop MEMS Accelerometers – the MAXL-CL-3000 family. Compared to our peers, Physical Logic is already setting itself apart through the performance characteristics of the Closed Loop family, such as better linearity, low sensitivity to environmental conditions and excellent long-term stability.

MAXL-Open Loop-2040 MEMS Accelerometer
Courtesy of Physical Logic

DD: Calibration, especially for the MEMS technology, is extremely costly for many inertial sensors. Can you describe how you calibrate your sensors, and how long for?

AF: Physical Logic developed test tools for calibration and final tests for multiple accelerometers. We calibrate and perform final acceptance tests on 100% of the accelerometers. Each accelerometer is provided to our customers with its acceptance test result, including bias and scale factor performance in temperature cycles, turn on performance and other parameters. Each Open Loop accelerometer is tested 12 hours under environmental conditions, while our Closed Loop accelerometers are tested for 48 hours and more.

DD: Industrial applications are in the sweet spot for low price and high-performance. And we also see some traction for inertial systems from the new space market. From your side, do you see any opportunities in these markets? Which other applications are you paying attention to for the near future?

AF: That is right. We have developed, and already are producing, ground-breaking MEMS products. Our Ultra-Low Noise Open Loop accelerometers provide huge advantages for a wide range of industrial systems such as tilt measurement, seismic sensing and robotic platforms. Our Closed Loop accelerometers, with Ultra-Low Vibration Rectification Error (VRE), are intended for use within high precision inertial navigation applications. And yet, in relation to several ongoing projects, we are forced to wait for MEMS gyros to be developed at the same level.

MAXL-Closed Loop-3030 MEMS Accelerometer
Courtesy of Physical Logic

DD: MEMS accelerometers were always moving faster to better performance, in contrast with MEMS gyroscopes where the evolution is slower. Do you think this accelerometer evolution will bring advantages for your company?

AF: Exactly. We feel that we are the front runner of this evolution. We would love to see MEMS gyros developed at the same level, because the high-end MEMS IMUs cannot be designed for operation without gyros. We believe that disk resonator gyroscopes (DRG) will be attractive candidates for high-performance MEMS gyroscopes. Results demonstrated so far show a true potential to achieve navigation-grade performance. We believe that MEMS IMUs designed with integration of DRG and our Closed Loop MEMS accelerometer will reshape the inertial sensing and navigation industry.

DD: Given that the lifecycle of many industrial-grade sensors is much shorter than for space, aviation and naval applications, does this necessitate a different approach to sensor design?

AF: Physical Logic’s accelerometers are uniquely designed using in-plane bulk micromachining technology to achieve higher performance and better reliability compared to out-of-plane or surface micromachining sensors. As a result we do not need to use vacuum packaging. We instead use seam welding at atmospheric pressure. This significantly increases the product’s life cycle and its resistance to harsh environmental conditions.

DD: What are the key advantages from the system designer’s point of view using your MEMS accelerometer for high performance applications?

AF: Compared to traditional electromechanical sensors, Physical Logic MEMS accelerometers meet the demand for low CSWaP, offering unmatched performance alongside better value to IMU/INS manufacturers and users.
The MAXL-CL-3000 family of accelerometers offers improved performance, such as scale factor linearity, bias stability and VRE.

DD: How difficult it is to replace traditional accelerometers with MEMS accelerometers?

AF: It always depends on competence level of the system. We are facing different technological approaches, and in most cases the initial system design is decisive. Nevertheless, some customers are expressing their flexibility and willingness to make PCB adaptation.
Physical Logic’s advanced MEMS technology enables customers to build an IMU that competes in price, performance and physical characteristics with the traditional mechanical sensors.
As a matter of fact, our flagship MAXL-CL-3030 Closed Loop accelerometers were adopted by several IMU/INS manufacturers worldwide, including Israel and North America.

DD: China is believed to be ramping up its domestic inertial volume production, especially on the MEMS side, to increase industrial and other autonomous-everything applications. Do you have a better view on the Chinese market? What is Physical Logic doing to penetrate better this market?

AF: We see an increase in demand from China, however, as an Israeli company under export control we can only serve the Chinese market in a limited way.

DD: How do you see the impact of the Covid-19 pandemic on this end-high inertial business? Did it affect you in some way?

AF: We are lucky that we have not been affected by Covid-19. We are constantly implementing all the necessary measures to maintain the safety of our professionals. And we are applying maximum effort to maintain manufacturing facilities operating to schedule. So far we have succeeded with on-time product delivery to all our customers and see continuing customer demand.

DD: What are the next steps forward for Physical Logic technology-wise and/or market-wise?

AF: Physical Logic is involved in several complex projects with different customers. This contributes to the expansion of our product portfolio and necessitates continuously modernizing our technological capabilities. We are purposefully moving towards achieving a strategic goal – to convince the market that a new era of high-precision MEMS accelerometers has arrived.

DD: What would be the main message that you would like to pass on and keep in our readers minds?

AF: Physical Logic is a steadily developing company, creating cutting edge MEMS accelerometers for multiple applications. We are young and flexible, and are proposing constantly innovative modifications of our unique products. We see ourselves as a front runner of MEMS technology evolution.
Physical Logic is simultaneously involved in several challenging technological projects, and we are confident that our company has the best accelerometers in the world.


Physical Logic - Aviram Feingold

Aviram Feingold has 30 years of experience in inertial navigation systems and in the semiconductor wafer-processing industry, both in R&D and production.
Prior to Physical Logic, Mr. Feingold worked in Al Cielo Inertial Solutions Ltd as a VP in engineering, managing process and product engineering as well as manufacturing and testing lines.
Prior to Al Cielo, Mr. Feingold worked for Chiaro Networks Ltd. as manager of the process engineering group. At Tower Semiconductors, he held several positions in process engineering, as Yield Enhancement leader, and as Photo-Etch R&D group leader.
Prior to this, Mr. Feingold worked for several years at AT&T Bell Laboratories in the Semiconductor Laser Device Department, in Murray Hill, New Jersey. While there, Mr. Feingold published over 30 papers on process and device characterization.
Mr. Feingold holds a Master’s degree in Materials Science Engineering from Stevens Institute of Technology in New Jersey.


Dimitrios Damianos - Yole Développement

Dimitrios Damianos, PhD joined Yole Développement (Yole) as a Technology and Market Analyst and is working within the Photonics, Sensing & Display division.
Dimitrios is daily working with his team to deliver valuable technology & market reports regarding the imaging industry including photonics & sensors.
After his research on theoretical and experimental quantum optics and laser light generation, Dimitrios pursued a Ph.D. in optical and electrical characterization of dielectric materials on silicon with applications in photovoltaics and image sensors, as well as SOI for microelectronics at Grenoble University, France.
In addition, Dimitrios holds an MSc degree in Photonics from the University of Patras, Greece. He has also authored and co-authored several scientific papers in international peer-reviewed journals.

Related reports

High End Inertial 2020 - Yole Développement

High-End Inertial Sensors for Defense, Aerospace and Industrial Applications 2020
High-end inertial sensors are still the backbone of systems that will enable autonomous transportation and the new space industry despite COVID-19.
Market & Technology Report – Updated in August 2020