Dr Chris Mills

Research Fellow

+44 (0)1483 682711

c.mills@surrey.ac.uk

18 ATI 01

About

Biography

Dr. Chris Mills is a member of the research staff within the Nanoelectronics Research Centre at the Advanced Technology Institute.

He has held previous post-doctoral research positions in the UK and abroad. He has completed research at the Centre for Nuclear and Radiation Physics, University of Surrey, and at the Department of Electronics and Electrical Engineering, University of Glasgow, and was awarded a Spanish Ministry of Science and Technology “Ramon-y-Cajal” postdoctoral fellowship to study at the Nanobioengineering laboratory of the Catalan Institute for Bioengineering, Barcelona Science Park, Spain. Throughout his post-doctoral work, Chris has concentrated on the characterisation and application of polymers in different aspects of engineering.

Chris completed his PhD under the supervision of Prof. Martin Taylor, at the School of Electronic Engineering, Bangor University, looking into the characterisation of a low band-gap semiconducting polymer and its development as a semiconducting polymer memory element.

Research

Research interests

My research interests are related to the characterisation and application of structural and electronically conducting polymers in different engineering aspects.

I am currently involved in the production and development of large area organic light emitting diodes (OLEDs) at the Advanced Technology Institute. This involves the production of thin film semiconducting polymer diodes, incorporating carbon nanoparticle-based charge transport layers, over large areas, for the efficient generation of light of different colours. The OLEDs require characterisation of their physical and electrical properties, using a variety of methods, as well as the characterisation of the emitted light with respect to colour and intensity.

For this, I regularly draw on my previous experience in polymer characterisation and device production, including my previous work on semiconducting polymer X-radiation detectors, the production of polymeric nanotechnology systems for biomedical applications, and the development of polymer-based sensor systems for a variety of applications, including gas sensors for the analysis of exhaled breath and lab-on-a-chip based sensor systems for deep vein thrombosis (DVT) markers.

Research collaborations

I have previously collaborated with diverse companies involved in the Microfabrication (Netscientific, UK, AMO GmBH, Germany), Nuclear (Centronix, BNFL, Lab Impex, NPL, all UK), Biotechnology (Oryzon, Spain), Health care (Haptogen [now Wyeth], UK) and Medical device (Helena Biosciences, UK) industries. I have also worked with non-profit making organisations, including the Centre for Nanotechnology, Microtechnology and Photonics (Cenamps [now CPI]), a north east of England based development office, and Anticoagulation Europe (ACE), a thrombosis patient support group.

I have been involved in the preparation of proposals for, and in the execution of, a number of national and European projects. These include:

“SMARTONICS: Development of smart machines, tools and processes for the precision synthesis of nanomaterials with tailored properties for Organic Electronics” EC FP7 (STREP) 310229
“Organic Radiation Detectors” STFC (MiniPIPPS) ST/F006667/1
“TheraEDGE: An integrated platform enabling Theranostic applications at the Point of Primary Care” EC FP7 (IP) 216027; “DVT-IMP: Deep Vein Thrombosis - Impedimetric Microanalysis System” EC FP6 (STREP) 034256
“MapTech: Training for Micro-Analytical Platform Technology” EC FP6 (Marie Curie) 020316-2
"Nano-2-life, A network for bringing NANOtechnologies TO LIFE”, EC FP6 (NoE) NMP4-CT-2003-500057
“CellPROM: Cell Programming by nanoscaled devices” EC FP6 (IP) NMP4-CT-2004-500039
“Nanobiosensors based on individual molecules” The Spanish Ministry of Science and Technology, Ramon y Cajal Fellowship.

Publications

Hashini M. Thirimanne, K. D. G. Imalka Jayawardena, Andrew Nisbet, Yonglong Shen, R. M. Indrachapa Bandara, Christopher A. Mills, Guosheng Shao, S. Ravi P. Silva (2020)Hybrid Multipixel Array X-Ray Detectors for Real-Time Direct Detection of Hard X-Rays, In: IEEE transactions on nuclear science67(10)pp. 2238-2245 IEEE

DOI: 10.1109/TNS.2020.3021612

X-ray detectors currently employed in dosimetry suffer from a number of drawbacks including the inability to conform to curved surfaces and being limited to smaller dimensions due to available crystal sizes. In this study, a hybrid X-ray detector (HXD) has been developed which offers real-time response with added advantages of being highly sensitive over a broad energy range, mechanically flexible, relatively inexpensive, and able to be fabricated over large areas on the desired surface. The detector comprises an organic matrix embedded with high-atomic-number inorganic nanoparticles which increase the radiation attenuation and within the device allows for simultaneous transfer of electrons and holes. The HXD delivers a peak response of 14 nA cm(-2), which corresponds to a sensitivity of 30.8 mu C Gy(-1) cm(-2), under the exposure of 6-MV hard X-rays generated by a medical linear accelerator. The angular dependence of the HXD has been studied, which offers a maximum variation of 26% in the posterior versus lateral beam directions. The flexible HXD can be conformed to the human body shape and is expected to eliminate variations due to source-to-skin distance with reduced physical evaluation complexities.