Multi-materials drop-on-demand inkjet technology based on pneumatic diaphragm actuator

Abstract

Micro-droplet jetting belongs to the field of precision fluid dispensing techniques. Unlike traditional subtraction manufacture process, micro-droplet jetting as an additive fabrication technique with features of non-contact and data-driven represents a new development trend of modern manufacturing process. In this paper, the design, fabrication and performance of a multimaterials drop-on-demand (DOD) inkjet system based on pneumatic diaphragm actuator were described. For capturing the droplet ejection process and measuring the droplet dimension, a self-made in situ imaging system based on time delayed external trigger was set up. The performance of the generator was studied by adjusting the structure and control parameters. Furthermore, the influence of fluid properties on the droplet ejection process was experimentally investigated. Micro-solderballs of 160.5 µm in diameter and UV curing adhesive micro-bumps of 346.94 µm in contact diameter with the substrate were produced. The results demonstrated that the DOD inkjet generator possesses characteristics of robust, easy to operate and maintain, and able to withstand high temperature as well as applicability to a wide variety of materials including polymers, low melting point resin and high melting point metal. The system has a great potential of being used in the fields of IC and MEMS packaging, 3D printing, organic semiconductor fabrication, and biological and chemical analysis.

On demand manufacturing of patient-specific liquid capsules via co-ordinated 3D printing and liquid dispensing

“…During liquid dispensing, although the distance travelled by the piston of the liquid dispenser motor remained identical for both 2 and 10 mL syringes, however the dispensed volume is significantly reduced by a syringe of smaller diameter. The control of liquid dispensing could also be achieved through the use of pneumatic liquid dispensers (Xie et al, 2010).…”

Microfluidic Jetting Deformation and Pinching-off Mechanism in Capillary Tubes by Using Traveling Surface Acoustic Waves

“…In particular, realizing microfluidic drop-on-demand jetting allows for complete discrete controllability of the whole jetting process, which mainly includes controlling the jetting droplet diameter, velocity, frequency and direction. At present, the types of droplet jetting methods according to the driving modes mainly include pneumatic [5], thermal bubble [6], piezoelectric [7], electromagnetic [8], mechanical [9] and ultrasound focusing [10]. For some microscale device applications, there are some drawbacks in these methods, such as the limited driving force and inconvenient control of air pressure supply in the pneumatic jetting device, the necessary condition for special liquids that can be heated and evaporated quickly in the thermal bubble jetting device, nonlinearity, creep, aging and hysteresis problems in piezoelectric ceramics, limitation in conductive metal liquid driven by Lorentz force in a magnetic field, mechanical wear of moving parts in a mechanical cavity and the highly complicated and costly components in the ultrasonic system.…”

“…Specifically, fluids undergoing jetting should have sufficient inertia to overcome the viscous stress and surface tension acting on the interface of the fluid and surrounding media [14]. Compared to other droplet-generation mechanisms in microfluidics such as pneumatic, bubbling, piezoelectric, electromagnetic, mechanical and ultrasonic vibration [5][6][7][8][9][10], the SAW-microfluidic jetting technology has the advantages of great force, high efficiency, flexible design, simple fabrication, cost-effectiveness, lightweight and miniaturization for easy integration, and relatively wide fluid viscosity range. The droplet jetting phenomenon actuated by SAW was first reported in the last decade of the twentieth century [18], in which radio frequency (RF) power for jetting has been concluded as between the effects of more RF power in simply moving the drop and the effects of less RF power in atomizing the drop.…”

Addressable multi-nozzle electrohydrodynamic jet printing with high consistency by multi-level voltage method

“…6,7 Firstly, E-jet printing can reach sub 100 nm resolution, [8][9][10] and can print fine structures with size much smaller than the inner diameter of the nozzle. [11][12][13] Secondly, E-jet printing is compatible with high viscous solution (>10000 cPs) [14][15][16] that is three order of magnitude higher than that of the traditional ink-jet printing (<20 cPs).…”