Heat concentrates.
So does our cooling.
Rheion controls cooling liquid flow on chip scale in immediate response to hotspots. No moving parts. No mechanical wear. Active reduction of boundary layer effects.
More than 50% of electronics failures or performance limitations are thermally related. AI, power electronics and high-density compute are driving heat flux levels beyond what conventional cooling can manage. Passive heat sinks, mechanical pumps, chillers and cold climates are no longer enough.
Thermal management has become a first order design constraint defining system performance, reliability, economics and lifetime.
We are changing that.
Combining
• Dielectric fluid for safe operations • Integrated local flow control • Surface improvements and micro-fin structures positioned chip-near • Active boundary-layer control • Near-zero system pressure
Eliminating
• Short circuit risks • Complex mechanical parts • High pressure drop and parasitic pumping losses • Single points of failure • Significant boundary layer heat transfer losses
Enabling
• Immediate cooling response at hotspots • Higher power per chip at lower ΔT (thermal losses) • Warm liquid cooling, operating at 30–40°C inlet and 45 to 60°C outlet • Reduced PUE and higher compute power per kWh energy consumption
Introducing Rheion™
Fluid movement without moving parts
Rheion™ delivers precision cooling based on liquid flow control at chip scale. Fluid motion is generated by electric fields interacting with charged species in dielectric liquid through ion-drag and conduction mechanism. With no moving parts, thermal interface material (TIM) related issues including warpage and aging are eliminated. Minimal maintenance requirements thanks to no mechanical wear.
Handles chip heat loads up to the kW range, including localized hotspots.
Typical flow: approximately 100 to 1,000 ml/min (scalable).
Power consumption: 0.1 to 1W.
Design lifetime: 7 to 20 years (approximately 200,000 hours MTBF).
The APR Rheion™ Cooling Architecture
Micro-fin structures combined with Rheion™ units
Sealed construction and re-supply of fresh coolant to high heat flux regions, eliminating boiling instability, vapor management complexity and system pressure spikes.
Sealed construction and re-supply of fresh coolant to high heat flux regions, eliminating boiling instability, vapor management complexity and system pressure spikes
Micro-fin structures positioned directly at the chip increasing heat transfer surface area by 2 to 4 times
Microchannels below 1 mm hydraulic diameter carrying dielectric fluid directly across chip surfaces at micrometer distance
One or multiple Rheion™ units positioned across a chip or system, each independently controlled to direct flow precisely where heat demands it
The APR Rheion™ Cooling Architecture delivers compact, high-power-density cooling for CPUs, GPUs and Power chips. It uses non-conductive dielectric cooling liquid, which operates safely in direct contact with electronics.
Boundary layer effects are actively controlled through electric body forces and optimized flow at both micro and macro scale. This enhances local fluid motion near surfaces, allowing micro-fin structures to disrupt the boundary layer and improve convective heat transfer by approximately 2–5 x.
Precise heat removal enables operation even with warm liquid cooling, supporting inlet temperatures of 30–40°C and outlet temperatures of 45–60°C — enabling chiller-free operation in many environments and facilitating better waste heat recovery.
Practical chip cooling capacity: 100 to 300 W/cm² (vs 20 to 50 W/cm² with conventional cooling)
Heat transfer coefficient improved by ~5–10×