Pumped Two-Phase Quality Sensor
Pumped two-phase (P2P) cooling systems are a commonly used thermal architecture that offers significant performance benefits over single-phase systems such as higher heat transfer coefficients and reduced fluid flow rates. A major challenge seen by P2P systems is the desire for optimal steady-state operation despite transient changes in heat load, which can be mitigated by sensing the quality of the two-phase flow present in the system. ACT has developed a novel, capacitance-based P2P quality sensor capable of registering across a quality range of 0 to 1 with a high degree of accuracy. The developed sensor solution is non-invasive as it allows the fluid to flow through without additional pressure drops or other flow disturbances. It is a simple and robust design, which is inexpensive and scalable to various tube diameters and working fluids.
Plasma-Powder De-Oxidation
Plasma, the fourth state of matter, is a highly reactive state that can be used to enhance or assist various chemical processes. Low-temperature plasma (LTP) creates a set of circumstances that enable chemical reactions without the adverse effects of material decomposition, melting, agglomeration, or sintering. One such chemical reaction is the reduction of metal oxides to form metal and water (MxOy → M+ H2O). Metal particles are used in a host of applications including energetic materials and 3D printing (i.e., additive manufacturing). When used (or even stored or transported) for these applications, the inherently thin layer of metal oxide on each particle surface grows, thereby changing the chemical and mechanical properties of the powders and any macro-scale parts manufactured from those powders. ACT is currently developing an LTP process that can reduce metal oxides from metal powders. Oxide content can be reduced as a pre-treatment prior to utilization/fabrication processes or as a post-treatment recycling process afterward. Oxides can be removed from metals and metalloids including copper, aluminum, steel, nickel alloys, and boron. If desired, ACT can also apply a plasma-enhanced chemical vapor deposition (PECVD) technique immediately after the LTP metal oxide reduction to passivate the reduced oxide particles. This PECVD passivation layer protects the particles from reoxidation during transport and storage in ambient conditions.
Publications:
1. P. Agrawal, D. Jensen, C.-H. Chen, R. M. Rioux, T. Matsoukas. “Surface-functionalized Boron Nanoparticles with Reduced Oxide Content by Non-thermal Plasma Processing for Nanoenergetic Applications.” ACS Appl. Mater. Interf. 13 (2021) 6844-6855.
CO2 Capture
ACT, in partnership with Lehigh University, has developed a novel acid/base ion-exchange direct air capture (DAC) system which can utilize either a low-grade heat source medium or an electrically derived weak base solution to regenerate the capture sorbent. This DAC sorbent has demonstrated CO₂ capture rates of greater than 90% with thermal regeneration of the sorbet shown to release captured CO₂ at temperatures as low as 50 °C with over 90% of the CO₂ released at a temperature of 100 °C. This novel system uses widely available commercial adsorbent resins, which reduce cost and alleviate supply constraints. Additionally, the system design is easily scalable and can be implemented as a modular system to minimize manufacturing and deployment costs.
