Advanced MEMS Sensors for Aerospace Applications
Dr. M. M. Nayak
Former Director, LVPO, ISRO
Various sensing devices and transducers are required in Aerospace Systems; such as Aircrafts, Helicopters, Launch Vehicles and Satellites; as well as for the Ground Segment, which includes tracking, telecommand, control, data dissemination, static testing, simulation tests, launch pad, launch operations and mobile links. Such sensors or transducers operate under extreme conditions: very high/low temperatures, severe vibration and mechanical shock, high acoustic levels, heavy wind load, electromagnetic interference, radiation, high vacuum and micro-gravity. The design of the sensors must take into account the aforementioned environmental effects as well as the medium in which the sensors are being used. For example, the sensing element may be immersed in pressurized liquid propellant of corrosive nature, under high temperature environment.
This talk is an overview that covers some of the important sensors for sensing pressure, temperature, level, depletion and acoustics; which are used in Helicopters, launch vehicles and satellites today, using well-proven conventional technology. The new generation of sensors viz. MEMS/NEMS based sensor technology for future use in Aerospace Systems is also covered in brief. Being miniature, integrating MEMS/NEMS sensors in a Micro or Nano Satellite system is much easier. The combination of reduced size, weight, and cost per unit through mass production, with increased functionality has significant advantage for Aerospace applications. Some of the major physical sensors, their classification based on the principle of operation, and spinoffs are going to be highlighted. A case study on the integration, assembly and packaging of MEMS Pressure Transducer, designed, developed and fabricated in-house for Aerospace applications, at CeNSE-IISc, is also presented. The acceptance, qualification tests, life cycling and reliability issues are also covered.
Dr. M. M. Nayak
Dr. Manjunatha Nayak received D.IISc and Ph.D.(Engg) degrees in Electronic Design Technology and Instrumentation respectively from IISc Bangalore following a Bachelor’s degree in Electrical Engineering from BMS College of Engineering Bangalore. He was awarded Ph.D. for his thesis titled "Sputtered Thin Film Strain Gauges & Pressure Transducer" in the year 1994. Subsequently he carried out his Post Doctoral research in Micro Electro Mechanical Systems ( MEMS) at University of Delft & Twente – Netherlands, under INSA Invitation fellowship programme, and at Toyohashi university, Japan under JSPS fellowship. He served in ISRO, Dept. of Space over 40 years, since 1971, in various capacities. Since then, he has grown professionally, from Technical Assistant to Scientist/Engineer ‘H’, and held dual positions as Deputy Director, Semi-Conductor Laboratory, Chandigarh and Director, Launch Vehicle Programme Office, ISRO HQ Bangalore. During his 39 years of service at Liquid Propulsion Systems Centre (LPSC) he has developed and productionised space qualified Pressure Transducers for PSLV, GSLV, GSLV M3, IRS, INSAT and Chandrayaan missions. The ultrasonic liquid level sensors, depletion sensors and temperature sensors for the Launch vehicle programmes of ISRO, digital pressure sensors for automatic weather stations & tsunami warning system were developed under his leadership and guidance. He was also responsible for realisation and export of about 8000 nos. of space qualified pressure transducers to European Space Programme, 25 nos. of high out-put transducers to USA and supply of more than 30000 nos of transducers to ISRO programmes. Various MEMS Sensors were designed, developed and fabricated with his guidance at SCL for automotive, radio sonde, wind tunnel and shock tube applications. In recognition of his outstanding contributions to ISRO’s programmatic activities in various capacities, he was awarded ISRO MERIT Award in 2008. He has also received several other awards for his academic excellence. The best paper award in NSI-1989, SEP France Vikas Agreement Completion award in 1989, NRDC award in 1985, NPE- 1984 special award and Kirloskar Electric company best student award are only a few examples of such recognitions. He has more than 81 publications in refereed international journals, 9 patents and has guided 10 research students. Superannuated from ISRO in June 2011, currently he is an Emeritus Professor at the Centre for Nano Science and Engineering, IISc, Bangalore, further pursuing his research activities in MEMS.