DIELECT

DIELECT: Dielectrophoretic roll system for high performance electronics using contactless selective assembly of nanostructures on large areas. Funded by EPSRC. £1M (Large Research Grants).

KEY STAFF AND PROJECT TEAM 

The DIELECT project is managed by Prof. Hadi Heidari. Other key academic staff from meLAB who are associated with the project are: 

Dr. Jungang ‘Judy’ Zhang and Dr. Venkatarao Selamneni (both RAs), with support from experienced team member Dr. Bhavani Yalagala. 

Figure 1 – The project team at its ‘kick-off’ meeting. From L to R: Benjamin King, Jonathon Harwell, Dr Bhavani Yalagala, Dr Venkatarao Selamneni, Prof. Jeff Kettle, Dr Roghaieh Parvizi, Dr Judy Zhang, Prof. David Cumming, Dr Mahmoud Wagih, Dr Morteza Amjadi, and Prof. Hadi Heidari. 

DIELECT’s Advisory Board (AB) comprises key industry partners – Emre Ozer (Arm), Richard Price (PragmaticIC), Neil Chilton (PEL), and Jeremy Davis (Semitronics).

PROJECT SUMMARY AND OVERVIEW 

DIELECT seeks to develop a novel instrument to exploit contactless-DEP forces to uniformly affix NWs over an entire substrate area or at defined locations – an approach which is inherently material, energy, and water efficient.   

Fig. 1 below illustrates the design structure, key assembly parts and various process steps for the successful integration of NWs from the solution(s) and device fabrication sequence. The process flow for the contactless integration of NWs is as follows: the target substrate belt, labelled as ‘6’ (where NWs will be printed) is passed through a cylinder into the first container labelled as ‘1’. This container is filled with the NW-A material. Within the container, a DEP electrode belt (labelled as ‘2’) is placed with the printed microelectrodes (MEA) designed to generate the electric field force in desired direction. Both belts i.e., substrate and electrode, are placed in such a manner that DEP force attracts NWs on the back side of the substrate belt (facing the solution side). In this way, the MEAs are not incontact with the electronic layer and hence the process is termed as ‘contactless’. 

AIMS AND OBJECTIVES 

DIELECT aims to develop a contactless roll to roll (R2R) Dielectrophoresis (DEP) equipment for the large-scale manufacturing of 1D nanowire based high performance devices and circuits. A 3D vertical CMOS IC using PMOS and NMOS transistors will be finished. It will enable a novel manufacturing methodology for the fabrication of the flexible and advanced IC using 1D nanostructures (V2O5, ZnO, Si, AgNWs, CuNWs).    

The overarching goal of DIELECT is to develop resource-efficient R2R DEP based pilot line (Fig. 1) allowing high-throughput assembly of NWs-based electronic layers and demonstrate their use for development of high-performance devices (e.g., sensors (temperature/photodetectors), transparent conductors, and CMOS circuits (switching frequencies > 1GHz) in various form-factors (inc. Flexible electronics). In this regard, the key objectives that will be pursued are to: 

Obj1. Develop the equipment for contactless roll DEP process. 

Obj2. Demonstrate the capability of developed equipment by obtaining multiple types of high-performance electronic layers (transparent conductive tracks, uniformly thick metallic NWs based layers, semiconductive NW based layers, 3D stacked layers etc.) on large area flexible substrates using a combination of materials and the extensive characterisation of their electronic/optical properties. 

Obj3. Fabricate high-performance (mobility >600 cm2/Vs, Switching frequency ~1GHz) devices, and printed CMOS circuits in various form-factors.

NEWS AND UPDATES 

The project team will be publishing a report soon detailing progress on design and fabrication for a contactless DEP, parameter optimisation, and post-treatment of aligned nanowires for enhanced performance. Check back soon for more! 

PUBLICATIONS AND PRESS  

A paper was presented on the project work to date at June’s UWO 2025 conference at University of Strathclyde by Dr Venkatarao Selamneni and Dr Carlos Garcia-Nunez. 

Dr Jungang ‘Judy’ Zhang also presented a poster on the project’s aims, demonstrations, and use cases, at the ‘Responsible Electronics and Circular Techologies’ (REACT) symposium, one of the launch events for the new flagship centre at UofG: https://www.linkedin.com/posts/james-watt-school-of-engineering_sustainable-electronics-activity-7330506531068596224-O42x  

She and the team have also submitted a paper for the forthcoming inaugural REACT conference: 1st International Conference on Responsibel Electronics (REACT)