4D-Printed Temperature-Controlled Flow-Actuated Solid-Phase Extraction Devices

Abstract

Four-dimensional printing (4DP) technologies can extend the functionality and applicability of manufactured analytical devices through employing stimuli-responsive materials. In this study, we used a photocurable resin of stimuli-responsive shape-memory polymers and digital light processing three-dimensional printing (3DP) to fabricate a smart sample pretreatment device featuring a solid-phase extraction (SPE) column and a temperature-controlled flow-actuated valve. Through manipulation of the temperatures and flow rates of the sample, eluent, and rinsing streams, we used this 4D-printed SPE device to extract Mn, Co, Ni, Cu, Zn, Cd, and Pb ions from high-salt content samples and remove the sample matrix prior to their determination by inductively coupled plasma mass spectrometry. After optimizing the valve design and operation and the analytical scheme, this device displayed competitive analytical performancethe method detection limits (MDLs) ranged from 0.7 to 22.1 ng L–1 for these metal ions (the MDLs ranged from 0.5 to 18.8 ng L–1 when validating the same printed SPE column using an online automatic system equipped with electric switching valves). Furthermore, we performed analyses of these metal ions in three reference materials (CASS-4, 1643f, and 2670a) and spike analyses of collected samples (seawater, ground water, river water, and human urine) to confirm the reliability and applicability of this analytical method. For the first time, 4DP has been used to fabricate a multi-functional, stimuli-responsive sample pretreatment device displaying analytical performance equal to that of a commercial apparatus. This novel approach builds upon the functionality and diversity of 3DP-enabling devices with the goal of developing more efficient analytical schemes.

4D-Printed Elution-Peak-Guided Dual-Responsive Monolithic Packing for the Solid-Phase Extraction of Metal Ions

“…Under the optimized operating conditions [P (NIPAM) mode] for the SPE column with the 4D-printed dual-responsive monolithic packing (Table S2; sample volume: 0.5 mL; sample throughput: 17.1 h –1 ), the absolute extraction efficiencies of the metal ions ranged from 91.9 to 95.1% [ratios of the elution peak areas (10 μg L –1 ) with and without extraction; Table ], their correlation coefficients ( R ) in the working range were all greater than 0.9997 (Figure S9A,B), and the enhancement factors (EFs) ranged from 13.0 to 19.3 [ratios of H max (10 μg L –1 ) after and before extraction , ]. Compared with previously reported 3D-printed SPE devices − and commercial SPE devices − for sample pretreatment and trace-element determination (Table S3), the SPE column with the 4D-printed dual-responsive monolithic packing developed in this study provided superior analytical characteristics, including much lower MDLs (under the minimum sample volume), higher throughput, and greater extraction capacities. To validate the applicability of our analytical method for the reliable determination of metal ions in natural water and urine samples, the concentrations of the investigated metal ions in an SRM and CRMs were measured.…”

“…Photocurable resins of the dual-responsive polymers were prepared by mixing NIPAM, tBA, HDDA, and TPO (25:56:18:1). TPO was used as the photoinitiator, NIPAM was used for its stimuli-responsive properties, − and tBA and HDDA were used for their shape-memory property. , …”

“…TPO was used as the photoinitiator, NIPAM was used for its stimuli-responsive properties, 54−60 and tBA and HDDA were used for their shape-memory property. 46,61 SPE Column with the 4D-Printed Dual-Responsive Monolithic Packing. The 3D object of the SPE column (Figure 1A) was modeled using SolidWorks 2020 (Dassault Systemes) and contained a set of demountable column holders and a replaceable monolithic packing.…”

“…Three-dimensional printing (3DP) technologies are highly applicable to the customization of diverse analytical devices featuring special geometric characteristics or functionality. − The coupling of 3D-printed SPE devices with atomic spectrometric techniques has been demonstrated to allow improvements in adaptability, diversity, and analytical performance for trace-metal analysis. − Moreover, emerging four-dimensional printing (4DP) technologies based on the 3DP of stimuli-responsive materials are capable of effectively fabricating stimuli-responsive analytical devices possessing time-dependent shape programming and/or shape-memory properties. − At present, studies utilizing stimuli-responsive materials to improve the analytical performance of conventional SPE schemes are limited. It is necessary to explore the capability of 4DP technologies for advancing SPE-based analytical schemes to develop future sample-preparation techniques.…”

Bioprinting for bone tissue engineering

“…Physical mainly includes temperature, light, electricity, and magnetic field (Figure 1A). Wu et al (Wu et al, 2021) presented an approach to imitating dynamic movements using hydroxybutyl methacrylated chitosan (HBC-MA). When the ambient temperature increases, additional thermal cross-linking of the photocross-linked HBC-MA hydrogels occurs.…”