EDITOR ’ S CHOICE PHOTOCHEMICAL ETCHING
PRECISION MICRO
Etching a new future for hydrogen electrolysers
As the world adapts to powering its vehicles , towns and cities with zerocarbon energy , the demand to upscale new technologies is gathering pace . Karl Hollis , Precision Micro ’ s Director of Engineering , looks at how bipolar plates , a key component used in electrolysers , could be made faster and more costeffectively using photochemical etching technology .
WHAT ARE ELECTROLYSERS ?
Electrolysers use electrical energy from wind , solar or hydroelectric sources to break water into hydrogen and oxygen . The green hydrogen produced can be used to power anything from buses and cars to generators , heating systems and machinery .
Bipolar plates feature precise , complex channels that distribute water evenly in the electrolyser stack . They are used to cool the electrolyser , supplying reactant gases to the anodic sides , and evacuating the hydrogen and gases produced during the reaction .
Though bipolar plates are important electrolyser components they are one of the most expensive , often costing up to 60 % of the stack cost . Chemical etching provides a viable manufacturing alternative for engineers looking to reduce this cost .
CHEMICAL ETCHING VERSUS TRADITIONAL MACHINING
Chemical etching uses etchants to create complex fluidic components such as bipolar plates and can offer huge advantages over traditional stamping and hydroforming .
The tooling used for stamping and hydroforming can be slow and uneconomical to produce . By comparison , chemical etching uses digital tooling which is inexpensive and offers greater flexibility to optimise designs .
Chemical etching uses digital tooling which is inexpensive and offers greater flexibility to optimise designs .
Bipolar plates are prone to distortion and surface roughness during conventional machining . As such , more complex designs can be challenging . Etching prints the design directly onto the material , offering almost unlimited part complexity . Also , each plate is 100 % burr and stressfree . This versatility enables designers to vary the size and shape of channels without additional cost and with accuracy to ± 0.020 mm .
CHEMICAL ETCHING : A VIABLE ALTERNATIVE
Hundreds of research papers explore the efficiency , quality and financial limitations of producing metallic bipolar plates . Many don ’ t consider chemical etching , a process that allows for complex , higher-performance bipolar plates in shorter lead times than conventional machining .
To learn more about the chemical etching process visit www . precisionmicro . com
30 PECM Issue 58