An inkjet/ultrafast laser hybrid for digital fabrication of biomedical sensors

The project focuses on developing a novel manufacturing method for high resolution digital patterning of functional materials for low volume manufacture of sensors using inkjet printing and laser ablation. The manufacturing challenges and future capability of the hybrid technology will also be researched.

Project overview

Current diagnostic capabilities such as microscopy, culture, immunoassays and nucleic acid amplification are mainly lab based analytical techniques and are expensive, time consuming and only performed by trained personnel [1]. Therefore we need to develop technologies to complement lithography that can enable the precise patterning of advanced functional materials that are often sensitive to lithographic processes.

This research focuses on defining a novel and versatile hybrid technology combining digital liquid deposition techniques and laser ablation to deliver advanced sensing devices. This hybrid technique will be able to provide low volume niche manufacturing on a broad range of surfaces where current lithography techniques are not feasible.

Figure 1: Hybrid Technology Combining Droplet Deposition and Ultrafast Laser Ablation for biosensing applications

Inks using functional and biological materials are formulated and then processed using inkjet printing and ultrafast laser ablation.

Inkjet Printing:

• Drop-on-demand
• Digitally controlled and used commercially for short print runs and late-stage customisation, with typical printheads containing 100 – 1000 nozzles.
• Traditionally used for graphical printing but has been demonstrated with biological and functional materials.
• Resolution within 10s of micrometres.

Some of the initial work on inkjet printing functional materials has been focused on the delivery of iron oxide catalyst on silicon substrates for the growth of structured carbon nanotube forests.

Ultrafast Laser Ablation:

• Digital control for ultra - precision patterning sub-micron resolution features
• Suitable for shaping biological and functional materials due to no thermal energy build up in the surface causing heat affected zones.

Some of the initial ultrafast laser patterning work has been focused on printed and PVD coated iron oxide catalyst on silicon wafers and looking at the effects of the laser on the nanocatalyst islands critical for the growth of carbon nanotube forests. Early experiments on some mCherry fluorescent protein have also been carried out.

Biosensing Applications

• Controlled growth and patterning allow different biosensor structures
• CNTs can be functionalised for biosensing applications achieving, high sensitivity and high speed detection
• Different proteins and biological materials can be patterned to achieve multidiagnostic capabilities

Partners and sponsors

MSOLV

• Develops, manufactures and markets industrial processing machines for large-area electronics applications.
• Develops new manufacturing processes using core technologies of laser materials processing and inkjet materials deposition.
• Manufactures sensors in small-to-medium volumes using these digital processes at its Oxford facility

The Centre for Science Technology and Innovation Policy (CSTI)

• Collaborative work to look at examining the manufacturing challenges of emerging technologies and ways of de-risking scale-up at an early age.

[1]       I. E. Tothill, “Biosensors developments and potential applications in the agricultural diagnosis sector,” Comput. Electron. Agric., vol. 30, no. 1, pp. 205–218, 2001.