Mr. Niclas Weigel Profile

Niclas Weigel

at Leibniz-Institut für Polymerforschung Dresden e.V.

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 5 March 2021 Presentation + Paper

Photopolymer formulations for µSL printing of hydrogel microstructures as swellable functional elements

N. Weigel, J. Thiele

Proceedings Volume 11637, 116370A (2021) https://doi.org/10.1117/12.2576485

KEYWORDS: Polymers, Microfluidics, Microsystems, BioMEMS, Additive manufacturing, Transparency, Printing, Polymerization, 3D printing

Read Abstract +

We present a library of resin formulations for projection micro-stereolithography (PµSL) consisting of 4-hydroxybutyl acrylate (HBA), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and poly(ethylene glycol) diacrylate (PEGDA), diluted with aqueous solutions of the photoinitiator lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate (LAP) and the photoabsorber tartrazine. By varying the concentration and molecular weight of PEGMEMA and PEGDA, the swelling ratios of as-PµSL-printed hydrogel microstructures in water are well tunable with a reversible volume increase ranging from 13% to 86%. Furthermore, we illustrate the influence of exposure time per 3D-printed layer on the swelling ratio of the hydrogels, as well as the swelling time. The minimum feature size of rectangular void structures achieved with an exemplary resin from our material library is approx. 71 μm, while rectangular microchannels at the surface of a PµSLprinted hydrogel made from the same photopolymer formulation exhibit cross-sectional dimensions designed at 54 μm x 50 μm. Based on this initial characterization, microfluidic devices are fabricated to elucidate dimensional changes of microchannels under different swelling conditions (e.g., free swelling and confined swelling inside a chamber or microfluidic device). In addition, we PµSL-print microscopic parts with tailored geometries (cylindrical, pyramidal) that are capable of completely closing microfluidic chambers made from commercially available Perfactory R11 resin in a time-dependent fashion. Our resin library provides 3D-printed hydrogels with micron-scale feature size combined with tunable water uptake, rendering them suitable for designing functional microfluidic units such as membranes, valves and pumps.

Proceedings Article | 4 March 2019 Paper

Multifunctional microfluidic devices from tailored photopolymer formulations

Max Männel, Niclas Weigel, Julian Thiele

Proceedings Volume 10875, 1087507 (2019) https://doi.org/10.1117/12.2514798

KEYWORDS: Microfluidics, Printing, Polymers, Polymerization, Additive manufacturing, Computer aided design, 3D printing, Microscopy

Read Abstract +

Here, we demonstrate the additive manufacturing of two key microvalve designs, namely Nordin’s and Quake’s microvalves, based on a formulation consisting of tri(propylene glycol) diacrylate (TPGDA) as a base material, diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator and Sudan1 as the UV-absorber via micro-stereolithography (μSL). Mechanical measurements of test prints show an average Young’s modulus of 15.7 MPa, which is eight times lower compared to several previous studies on 3D-printed microvalves and micropumps based on poly(ethylene glycol diacrylate) 255 (PEGDA-252). We use a high-resolution Cerafab7500 printer (Lithoz GmbH, Vienna) with a minimal lateral resolution of 10.3 μm to print membrane valves with voxel dimensions down to 60μm. Particularly, we study the effect of different comonomers added to the photopolymer formulation – neopentyl glycol propoxylate (1 PO/OH) diacrylate (NPGPDA), 1,6- hexanediol diacrylate (HDDA) and 2-phenoxyethyl acrylate (POEA) – on the layer thickness, which is identified to be a crucial parameter. 3D-printed valves are tested regarding maximum operating pressure withstanding pressures of up to 5 bar. We show that TPGDA-based resins combine high flexibility, mechanical stability, and sufficient resolution for the future design of flow control units in microfluidics.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years