The automotive and aeronautic industries are looking for more lightweight materials to reduce the weight of the future cars and airplanes, and ultimately the fuel they consume and pollution they produce. Among the devices that contribute the mass of vehicles are an array of sensors. in a recent Nanotechnology article, researchers from the Institute of Microtechnologies in Bucharest, Romania, and the Academy of Sciences and Technical University in Chisinau, Republic of Moldova, report on flexible, ultra-lightweight pressure sensors based on graphene aerogel decorated by piezoelectric SnO2 or GaN nanocrystalline thin films.

 

Future cars and aeroplanes will contain large arrays of sensors that are sometimes termed electronic skin (e-skin). E-skin consists of huge amounts of individual sensors that are usually mounted on the body to monitor people’s health. Being the lightest material known today, graphene aerogel is highly recommended for lightweight applications. It is an extremely porous (degree of porosity > 99 %) three-dimensional ultra-lightweight material formed from randomly distributed graphene networks with a very low density (0.2g/cm3 < 3g/cmsup>3).

 

 

The researchers decorated their graphene aerogel with SnO2 and GaN films, as this significantly increases the piezoresistance of graphene aerogels. Both pressure sensors are flexible, ultra-lightweight (weight around 500μg) and exhibit a good responsivity which is one order of magnitude higher than that inherent to pressure sensors based on graphene suspended membranes. In conclusion, one of the lightest pressure sensors ever known has been demonstrated.

About the authors

Mircea Dragoman has been a senior researcher at the National Research Institute in Microtechnologies since 1996. He has been teaching at the University Politehnica Bucharest, Romania, since 2008. The course termed Advanced Technological Processes which is related to nanotechnologies and advanced materials. He has realized the first carbon nanotube and graphene devices and circuits for high frequency applications enriching the novel area of carbon-based electronics. In the period 1992-1994 he was the recipient of the Humbold Fellowship award and he has followed postdoctoral studies at Duisburg University, Germany. He was an invited professor at: CNR-Istituto di Electtronica dello Stato Solido-Roma (1996), Univ. Saint-Etienne – France (1997), Univ. Mannheim (1998-1999, 2001-2002), Univ. Frankfurt (2003), Univ. Darmstadt (2004); in the period 2005-2006, 2008-2010 he was nominated directeur de recherche at CNRS LAAS Toulouse. He published more than 250 scientific papers in the following areas: nanoelectronics, microwaves, MEMS, optoelectronics and co-authored 6 books published at Springer, Elsevier and Artech House in several editions.

Ion Tiginyanu is a senior researcher at the Institute of Electronic Engineering and Nanotechnologies and serves as first vice-president of the Academy of Sciences of Moldova, director of the National Center for Materials Study and Testing, and professor at the Chair of Microelectronics and Biomedical Engineering of the Technical University of Moldova. He published pioneering papers in the field of porous III-V and II-VI compounds, invented the technology of surface charge lithography and currently contributes to the development of novel flexible electronic and photonic materials. In 1995–96 and 1998-99 he has been a Humboldt research fellow at the Institute of High-Frequency Electronics of the Technical University Darmstadt, Germany, while in 2001 – a visiting professor at the Department of Electrical Engineering and Computer Science of the University of Michigan, USA. He has 350 international journal publications, 52 technological patents and co-edited 6 books on materials science and nanotechnologies in Springer, Woodhead Publishing etc. He is Honorary Member of the Romanian Academy, Honorary Doctor of the Joint Institute for Nuclear Research in Dubna, senior member of SPIE etc.

 

http://nanotechweb.org/cws/article/lab/67197