My multidisciplinary research interests include Flexible and Printable Electronics, Electronic Skin, Robotic Tactile Sensing, Bendable electronics device modelling, Micro/Macroelectronics and System Integration. Details of my group’s research are available at BEST Group Website. Some of my project are described below.
1. ‘PRINTSKIN’ – EPSRC Fellowship for Growth – Printable Tactile Skin.
PRINTSKIN will develop a robust ultra-flexible tactile skin using an innovative methodology involving printing of high-mobility materials such as silicon on ultra-flexible substrates such as polyimide. The tactile skin will have solid-state sensors (touch, temperature) and electronics printed on ultra-flexible substrates such as polyimide. The silicon based ultra-thin active-matrix electronics in the backplane will be covered with a replaceable soft transducer layer. The skin will be validated on the state-of-the-art robotic hands. This new technological platform to print tactile skin will enable an entirely new generation of high-performance and cost-effective systems on flexible substrates.
2. ‘FLEXELDEMO’ – Flexible Electronic Device Modelling.
Flexible electronic research has thus far explored various materials and fabrication techniques. Whilst these are important areas, device modelling and circuit design is critical for taking the research closer to manufacturing. The acceptable degree of bendability for reliable operation of devices and circuits is a question that has not been addressed so far. This is a challenging because the standard transistor models for circuit simulation programs such as SPICE do not take into account the dynamic bendability induced effects. FLEXELDEMO will address these challenges by systematically characterizing the ultra-thin chips, identifying various parameters that change with bending, and suggesting improved BSIM models for devices over bendable substrates.
3. ‘CONTEST’ – Collaborative Network for Training in Electronic Skin Technology.
This European Commission funded Marie Curie Actions Initial Training Network is investigating various critical aspects of flexible electronics – all converging towards obtaining an electronically-enhanced and wearable smart skin. The silicon and organic materials based solutions are being investigated to obtain systems with the advantages of both. My team members are exploring different techniques to integrate silicon based device on flexible substrates and obtaining reliable operation.
Further details available at www.contest-itn.eu
4. ‘Flexsensotronics’ – Flexible Sensors and Electronics.
The aim of this Marie Curie individual project was to develop mechanically flexible sensors and electronic systems for wearable electronics and electronic skin applications. The challenges included processing and combining stiff and brittle device materials with soft and compliant substrates while ensuring proper electrical functionality of the devices (when they undergo mechanical deformations). The two methodologies adopted in this project are:
(a) Microstructures based approach: The micro/nanostructures such and micro/nanowires and ribbons are obtained using top-down fabrication method. These micro/nanostructures are then transferred printed onto flexible subtrates in such as way that they result in electronics devices and circuits. Some results are shown in the figures below:
(b) Ultra-thin Flex-Chip Approach: The ultra-thin and mechanically flexible silicon chips are obtained by thinning down the conventional wafers and the transferring the these chips to flexible substrates. This Flex-Chip approach is complimentary to the micro/nanostructures based approach. Some results are shown in the figures below:
5. POSFET Tactile Sensing Arrays
The goal of this project was to develop POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) tactile sensing arrays using piezoelectric polymers and MOS transistor. A reliable fabrication process, including the deposition, patterning and poling of piezoelectric polymer films on a silicon chip, was developed for fabricating the high resolution tactile sensing arrays. The POSFET research has now advanced towards tactile sensing system on-chip – with tactile sensing arrays and on-chip basic electronics. Some results are shown in the figures below:
6. Italian MIUR PRIN-2007 Project
The aim of this project was to develop POSFET touch sensing devices based tactile sensing system including interface electronics for the humanoid robot ‘i-cub‘.
Details available at Tactile Sensing System for Humanoid Robots using Piezo-polymer-FET devices
7.. European Commission funded Project ‘ROBOSKIN’ (Details at:www.roboskin.eu)