SubSurface – Rapid Scale-up of Custom Cooling Solutions Through an Innovative Sub-surface Channelling Technique

"Power Electronics, Machines and Drives (PEMD) are technologies that enable the control and delivery of electrical energy and includes propulsion in transportation, energy generation and distribution, industrial machines and robotics. They are used in supply chains, like conductors and semiconductors, converter/inverter systems, \[and\] novel electric motor topologies." (KTN, InnovateUK)

Efficient and effective thermal management of PEMD is evolving. Optimisation of thermal management products to match ever-higher power densities, whilst reducing weight and footprint, has created an urgent need for innovation in heatsink and cooling plate technology.

The increased power densities of electric vehicle (EV) batteries and high-power electronics have led to heat generation at rates beyond the ability to simply air-cool them. Just as many living organisms regulate their temperature by circulating blood throughout their bodies, the next step for thermal management in these high-performance products is to also circulate a cooling liquid. However, contrary to living organisms that biologically grow an interconnected network of blood vessels, manufacturing similar passages inside of parts is a significant engineering challenge. Current solutions, as operated by _PSL Assemblies Ltd_ (PSL), require combining multiple materials and many labour-intensive steps.

_TWI Ltd_ (TWI) has recently invented a new sub-surface machining technique called CoreFlow(TM). It reaches through the outer "skin" of a part to remove the inside "core" of it, all without removing the outer skin. This new solid-state process allows for the creation of sub-surface networks of channels to be created within solid metal parts directly, thus enabling smaller form-factor and lighter thermal management components. Furthermore, it is digitally driven allowing for the creation of customised sub-surface network sizes and patterns without the need for additional tooling. This approach has transformative potential for producing higher-performance thermal management solutions with elevated reliability.

**_The main drawback of this approach is that it relies on costly specialised manufacturing equipment._**

_Hybrid Manufacturing Technologies Ltd_ (HMT) modularises specialist processes into heads that are useable on mainstream machine tools (the most foundational metalworking tool in the manufacturing industry). In the _SubSurface_ project HMT will migrate the CoreFlow(TM) process invented by TWI into a highly accessible and cost-effective solution, retrofittable to existing CNC machines. This will allow the formation of sub-surface networks and external machining to be accomplished in one machine and drive competitiveness and performance to new heights. This will empower _PSL_ and associated UK industry unprecedented leadership in thermal management solutions to enable next-generation PEMD technologies and bespoke liquid-cooled products.