Replication of micro/nano-scale features by micro injection molding with a bulk metallic glass mold insert

Zhang, Nan; Chu, Jingsong; Byrne, Cormac; Browne, David J.; Gilchrist, Michael D.

doi:10.1088/0960-1317/22/6/065019

Cited by 82 publications

(71 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The smallest feature can reach 85nm and was well replicated by the microinjection molding process using HDPE. Such patterns present aspect ratio dependent replication and lower aspect ratio regions have better filling than high aspect ratio regions, which is related to polymer flow resistant and local heat transfer [22]. Here we demonstrate a multi-scale mold fabricated by using FIB milling and FIB deposition, which provides an efficient method to fabricate nano-scale testing channels for DNA operations.…”

Section: Bmg Insertmentioning

confidence: 95%

Manufacturing microstructured tool inserts for the production of polymeric microfluidic devices

Zhang

Srivastava

Kirwan

et al. 2015

J. Micromech. Microeng.

View full text Add to dashboard Cite

Abstract:Tooling is critical in defining multi-scale patterns for mass production of polymeric microfluidic devices using the microinjection molding process. In the present work, fabrication of various microstructured tool inserts using stainless steel, nickel and Bulk Metallic Glasses (BMGs) is discussed based on die-sinking EDM (electrical discharge machining), electroforming, Focused Ion Beam milling and thermoplastic processes. Tool performance is evaluated in terms of surface roughness, hardness and tool life. Compared to stainless steel, nickel and BMGs are capable of integrating length scales from 10 0 to 10 -8 m and are good candidates for producing polymeric microfluidics. Selection of tool materials and manufacturing technologies should consider the end-user requirements of actual applications.

show abstract

Section: Bmg Insertmentioning

confidence: 95%

Manufacturing microstructured tool inserts for the production of polymeric microfluidic devices

Zhang

Srivastava

Kirwan

et al. 2015

J. Micromech. Microeng.

View full text Add to dashboard Cite

show abstract

“…In response to the trend for miniaturization of devices, products and components in the medical, optical and telecommunication industries, microinjection molding has been developed successfully as a mass production technology for small, high precision, high value-added products [1][2][3]. Microinjection molding involves two typical products: micro components weighing a few milligrams or large parts having micro/nano scale surface features.…”

Section: Introductionmentioning

confidence: 99%

Effects of gate design and cavity thickness on filling, morphology and mechanical properties of microinjection mouldings

Zhang

Choi

et al. 2015

Materials & Design

View full text Add to dashboard Cite

Miniaturized parts weighing single or tens of milligrams represent a large category of microinjection moulded products. Both miniaturization and extreme processing under microinjection moulding subject material to high shear rates and high cooling rates, and cause the same material to have different morphologies and final properties when used in conventional injection moulding. It also makes mold design challenging. This study investigates the effects of micro gate design (opening and thickness) and cavity thickness (100-500μm) on filling, morphology and the mechanical properties of miniaturized dumbbell parts. It is found that a reduction of gate size has two conflicting effects, namely, increased shear heating increases flow length, and increased cooling rate reduces flow length. Filling increases significantly with an increase of cavity thickness. In addition, the thickness of the skin layer reduces from ~70% to ~10% when part thickness increases from 100μm to 500μm. This oriented skin layer determines molecular orientation and broadly influences Young's modulus, elongation and yield stress. Natural aging at room temperature induces an increase of modulus and yield stress, and a decrease of strain at break. The mechanical properties of microinjection moldings is significantly different from those of conventional injection moldings and measurement at microscale is required for miniaturized product design. 1 Effect of Gate Design and AbstractMiniaturized parts weighing single or tens of milligrams represent a large category of microinjection moulded products. Both miniaturization and extreme processing under microinjection moulding subject material to high shear rates and high cooling rates, and cause the same material to have different morphologies and final properties when used in conventional injection moulding. It also makes mold design challenging. This study investigates the effects of micro gate design (opening and thickness) and cavity thickness (100-500μm) on filling, morphology and the mechanical properties of miniaturized dumbbell parts. It is found that a reduction of gate size has two conflicting effects, namely, increased shear heating increases flow length, and increased cooling rate reduces flow length.Filling increases significantly with an increase of cavity thickness. In addition, the thickness of the skin layer reduces from ~70% to ~10% when part thickness increases from 100μm to 500μm. This oriented skin layer determines molecular orientation and broadly influences Young's modulus, elongation and yield stress. Natural aging at room temperature induces an increase of modulus and yield stress, and a decrease of strain at break. The mechanical properties of microinjection moldings is significantly different from those of conventional injection moldings and measurement at microscale is required for miniaturized product design.

show abstract

“…MEMS and Microsystems (MST) technologies are creating a huge market for micro components and parts with micro/nano scale features [1]- [3], such as micro gears and microfluidic devices. Micro injection molding is a key enabling fabrication technology for mass production of polymer micro components.…”

Section: Introductionmentioning

confidence: 99%

“…Using this optimization, we measured the thermo-rheological behavior of polymer melt with two combined PT sensors. By using a Bulk Metallic Glass (BMG) mold insert, we successfully replicated a series of micron and submicron scale features [2], [3]. Based on process and rheological characterization, we can now propose process based quality control strategies for replicating micro/nano features.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Micro Injection Molding Process for the Replication of Micro/Nano Features Using Bulk Metallic Glass Insert

Zhang¹,

Browne²,

Gilchrist³

2013

IJET

View full text Add to dashboard Cite

Abstract-Microsytems are motivating the development of complex, net-shape products weighing a few milligrams or having micro/nano features. Such small components or micro/nano features are subject to extreme shear rates and thermal gradients in the micro injection molding process due to their large surface to volume ratio. Detailed process monitoring and characterization are desirable to create a viable manufacturing process with acceptable part quality for MEMS and Microsystems. This work covers the replication of micro/nano scale features using Bulk Metallic Glass (BMG), implementation of a suite of PT (pressure and temperature) sensors on a commercial reciprocating micro injection molding machine, and detailed analysis of the relationship between process-rheology-replication. The results indicate that injection velocity dominates the average viscosity of polymer melts; holding pressure can adjust the input pressure history for micro/nano features and mold temperature can enhance feature filling by elevating the polymer-mold interface temperature. Tailored strategies to set machine parameters for different molds and plastics can be developed to meet the quality requirement for both small components and micro/nano features.

show abstract

Replication of micro/nano-scale features by micro injection molding with a bulk metallic glass mold insert

Cited by 82 publications

References 48 publications

Manufacturing microstructured tool inserts for the production of polymeric microfluidic devices

Manufacturing microstructured tool inserts for the production of polymeric microfluidic devices

Effects of gate design and cavity thickness on filling, morphology and mechanical properties of microinjection mouldings

Characterization of Micro Injection Molding Process for the Replication of Micro/Nano Features Using Bulk Metallic Glass Insert

Contact Info

Product

Resources

About