Kim Hyeonseok, Velásquez-García Luis Fernando
Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
Microsystems Technology Laboratories, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
Adv Sci (Weinh). 2025 Apr;12(13):e2413706. doi: 10.1002/advs.202413706. Epub 2025 Feb 11.
This study reports the proof-of-concept demonstration of novel, additively manufactured, droplet-emitting electrospray emitter arrays for CubeSat thruster applications. The modular thruster design incorporates multiscale features by employing two different vat photopolymerization technologies, i.e., digital light processing for defining mesoscale features, and two-photon polymerization for creating microscale features. The thruster design includes optimized, 50 µm-diameter microfluidic channels to attain uniform emitter array operation. Devices with up to 8 modules of 4 emitters were tested in a vacuum to assess their performance. Stable and uniform electrospray emission was achieved across all emitters, with a near 100% transmission across the extractor. Both pressure (flow rate) and voltage modulation are investigated as methods for controlling the emitted current and, by extension, the thrust generated by the devices. The per-emitter current followed a well-known square root relationship with flow rate; in addition, a linear relationship between per-emitter current and extractor voltage is observed. Compared to pressure control, modulating thrust via voltage control simplifies system design, eliminating the need for complex valves and enabling a wider throttle range. Estimated thrust and specific impulse are comparable to, or better than reported droplet-emitting electrospray thrusters. These findings demonstrate the potential of additive manufacturing to implement electrospray propulsion hardware.
本研究报告了用于立方星推进器应用的新型增材制造的液滴发射电喷雾发射器阵列的概念验证演示。模块化推进器设计通过采用两种不同的光固化技术纳入了多尺度特征，即用于定义中尺度特征的数字光处理和用于创建微尺度特征的双光子聚合。推进器设计包括优化的50微米直径微流体通道，以实现均匀的发射器阵列运行。对具有多达8个模块、每个模块4个发射器的装置在真空中进行了测试，以评估其性能。在所有发射器上均实现了稳定且均匀的电喷雾发射，在提取器上的传输率接近100%。研究了压力（流速）和电压调制作为控制发射电流进而控制装置产生的推力的方法。每个发射器的电流与流速遵循众所周知的平方根关系；此外，观察到每个发射器的电流与提取器电压之间存在线性关系。与压力控制相比，通过电压控制调制推力简化了系统设计，无需复杂的阀门，并实现了更宽的节流范围。估计的推力和比冲与已报道的液滴发射电喷雾推进器相当或更好。这些发现证明了增材制造在实现电喷雾推进硬件方面的潜力。
