Subscribe to our newsletter to receive the latest news and events from TWI:

Subscribe >
Skip to content

World's most precise weld made at TWI

Back to Media and Events 2013-07-creepimage-inspecting-creep-damage-in-critical-power-plant-components 2016-09-cutting-edge-technology-for-nuclear-decommissioning A career in welding inspection Additive manufactured medical implants to enter mainstream Additive Manufacturing UK Strategy update available for download Advanced electron beam facilities meet advanced industrial challenges Advanced ultrasonic full matrix capture inspection software launched Armourers & Brasiers' awards open for entries Art exhibition leads to new method of laser metal deposition Asbestos detection made easier and more reliable ASME issues White Paper on auditing of welding Audit shows TWI as integral to innovation Aviation Industry Corporation of China collaborates with TWI BeamAssure™ – electron beam welding quality assurance tool Best practice for nuclear construction industry welding BS 7910:2013 - Assessing flaws in metallic structures Call for papers: 12th International FSW Symposium CII and TWI awareness seminar in composites technology Coatings and surface engineering: addressing the needs of industry Combatting ice and erosion in extreme low temperatures - EIROS Combining Cathodic Protection with Aluminium Coatings CROWN project commended for offshore wind corrosion work Depositing silicon carbide coatings by thermal spraying Digital Twin Technology to monitor offshore assets Digital twin technology wins environmental business award Dr Melissa Riley presents paper at international conference Dr Melissa Riley represents TWI at international conference eLearning package for CSWIP 3.1 Welding Inspector launched Entry is now open for SkillWeld 2016 Extending Aircraft Life Using Cold Spray Technology Familiarisation Course to EN ISO 3834 Fibre delivered laser beam cutting optimisation Friction stir welding – joining the future of industry Friction stir welding and Japanese jewellery Government funds £10 million technology hub in Teesside Has your PCN NDT Certification been voided? TWI Can Help… Her Royal Highness The Princess Royal opens new laboratories at TWI High-pressure hydrogen testing at TWI Ice-repellant coating for aerospace and energy industries Industry benefits of composites microwave processing Innovation Centres at TWI deliver progress for industry INTRAPID produces rapid in-line laser AM inspection systems Introducing the TWI Virtual Academy: studying on your own terms Investigating geothermal coatings for the future of renewable energy Laser scanner improves TWI weld analysis services for Members Lasers for decommissioning: the story so far Lifting the lid on innovation: exploratory projects at TWI Lord Heseltine opens new TWI technology and training centre Meeting reinvigorates Welding Institute's Liverpool branch Mike Russell appointed as TWI Operations Director 'Mind the doors' – New project investigates train door failure Mobile electron beam welds for fabricating large structures ModuLase - combining laser processes for the future of manufacturing MoU between ALFED and TWI enhances collaboration Nanosecond pulsed laser expands opportunities for project work NDT Voiding of PCN certification from NDT International New benefit for TWI Members: free access to Welding Abstracts journal New building to house TWI's structural integrity expertise New centre for Advanced Manufacturing Technologies launched New eBooks added for Professional and Industrial Members New facility for testing the barrier performance of polymers New fracture testing accreditation New Granta Centre manager guarantees premier conferencing New home and new capabilities for TWI in Middlesbrough New manufacturing process supports Hayter's winning position New sensor technology for safe shale gas extraction funded New TWI article breaks down the changes to ISO 15614-1 New ultrasonic testing courses from the TWI Virtual Academy New welding apprenticeship standards receive government approval Novel solution for submersible pumps in oil and gas industry Open Day sparks the start of a new era of research for TWI Pioneering tests being conducted on bespoke TWI rig Plant Inspection training meets need for competent workers Plastics welding experts answer your questions at Aquaculture UK 2014 Progressing graphene as a supercritical fluid barrier Project investigates Powder Metallurgy for astrospace use Purpose-built pressure testing facility opens for business at TWI Purpose-built pressure testing facility to be constructed at TWI Registration opens for TWI BS EN ISO 15614-1 (2017) training RJD Engineering gains Factory Production Control system Certification Rolls-Royce's Martin Boyd discusses the benefits of becoming an IEng Showing expertise in corrosion safety, investigation and assessment Simulating real-world conditions for oil and gas research Skills Development Fund Scheme provides extra TWI courses SkillWeld medallist goes on to take gold at EuroSkills 2016 SOCAR and TWI celebrate new competence training partnership Success for TWI's first blended learning course candidates Successful engineers graduate from EWF/IIW Diploma in Welding 'SUPERSLAB' to meet thicker high-strength steels challenge SurFlow: secure, robust, integrated data transfer through composites Symposium highlights developments in linear friction welding Taking the next step as a CSWIP Welding Inspector Tate Modern use solvent technology for art restoration Teletest business transfers to Eddyfi Technologies The 50-year view of fracture The Transport Systems Catapult and TWI Announce Partnership The Welding Institute Annual Awards and Dinner 2017 The Welding Institute Awards 2018 – Applied Technology Award The Welding Institute promoting career development at NECR exhibition True Stress-True Strain Tensile Testing to Failure TWI and Lloyd's Register launch Fullagar Technologies initiative TWI and Lloyd's Register projects advance take-up of AM TWI celebrates National Women in Engineering Day TWI CEO Christoph Wiesner awarded OBE TWI combines heritage with innovation for the Morgan Motor Company TWI commence 'SubSeaLase' decommissioning project TWI delivers plastics welding training course to Fusion Marine TWI develops essential metallography training to ensure best practice TWI enters research centre agreement with AECC BIAM, China TWI helping UK businesses to 'Access India' TWI helps bring Philips Avent's thermoplastic nebulizer to market TWI helps Engineering College meet industry demand for staff TWI holds successful cold spray technology course TWI hosts graduation ceremony for EWF/IIW Diploma engineers TWI joins 'Integral' nuclear waste project TWI lands NDA innovation award for nuclear decommissioning TWI launches course for advanced digital radiography TWI pioneers 'invisible weld' process TWI Pioneers New Dissimilar Weld for European Space Agency TWI rewards outstanding undergraduate engineering projects TWI signs Memorandum of Understanding with Saudi Aramco TWI Supports Underwater Laser Cutting Project TWI Technology Fellow given Visiting Professorship at LSBU TWI Training success story - Vera Dragoi TWI wins RIBA Awards TWI working to progress composites in the automotive industry TWI's Dr Philippa Moore: A role model for female engineers TWI's Dr Shiladitya Paul called as guest editor of Coatings journal Ultrasonic imaging climbing robot passes field trials Update on CPD for Welding Institute Professional Members Vince Cable India visit promotes UK business successes Welding Institute Annual Awards 2018 Welding Institute's latest Engineering Council registrants Welding the unweldable: TWI friction stir welds ODS steel WindTwin project to revolutionise wind turbine technology Workshop to address dissimilar materials joining challenge World's largest linear friction welded component produced World's most precise weld made at TWI
 
02 June 2015

A novel welding technique enabled by electron beam lithography involving laser welding along absorber dye patterns has been developed by TWI Ltd in collaboration with the University of Cambridge. The result is the world's smallest weld in thermoplastic material, bringing with it new applications for smaller scale biological analysis chips, chemical micro-reactors and electronics products.

Laser welding is the process of choice in many industry sectors for joining plastics due to its ability for precision of the joint location and in the amount of heat applied. It is perfectly suited to the manufacture of complex products such as microfluidic devices, where channels and structure resolution below 100 μm are used regularly.

As industry seeks to produce even smaller scale complex plastic components, there is a call for new research to allow welds in plastics of 10 μm and below. Until recently, the smallest laser welds possible measured between 10 and 20 μm in width. However, this is at an infrared laser's resolution limit, and smaller welds are not possible using control of the laser focus spot size alone.

It was work carried out by TWI and the University of Cambridge's Cavendish Laboratory into precise patterning of laser absorber dye on a plastic surface to define weld position, that sparked off the latest advance. Having proved that the process using laser absorber dye resist material could allow joints to be made between plastics, the project team studied the use of electron beam lithography to pattern the absorber and enable welds with a width smaller than 10 μm, mimicking methods used to build microelectronic circuits. The challenge was to generate micro-channels and infrared absorber tracks at their edges simultaneously, and to seal the channels.

With polymethyl methacrylate (PMMA) thermoplastic as a base material, the team carried out trials, following the principle of transmission laser welding using a thin coating of infrared absorbent material at the joint interface. The coating was patterned using electron beam lithography to the required resolution in a reproducible manner, so it could be retained after welding. Joint strength was ratified using larger-scale samples.

EB lithography and diode laser welding - key to achieving the world's smallest welds in plastics
EB lithography and diode laser welding - key to achieving the world's smallest welds in plastics
EB lithography and diode laser welding - key to achieving the world's smallest welds in plastics
World's most precise weld made by Cambridge laboratory
Welds in PMMA, 0.5 microns wide at 5 micron intervals

The trials culminated in successful demonstration of a series of laser welded joints with widths of 1 μm and channels of 5 μm. Smaller welds with 0.5 μm were also demonstrated leading to the conclusion that it is possible to make plastics components with a high density of structure and resolution below 1 μm, and that welding can be applied without excessively heating regions outside the weld lines.

For further information, please contact us.

For more information please email:


contactus@twi.co.uk