The ability to interface microfluidic devices with native complex biological architectures, such as whole organs, has the potential to shift the paradigm for the study and analysis of biological tissue. Here, we show 3D printing can be used to fabricate bio-inspired conformal microfluidic devices that directly interface with the surface of whole organs. Structured-light scanning techniques enabled the 3D topographical matching of microfluidic device geometry to porcine kidney anatomy. Our studies show molecular species are spontaneously transferred from the organ cortex to the conformal microfluidic device in the presence of fluid flow through the organ-conforming microchannel. Large animal studies using porcine kidneys (n = 32 organs) revealed the profile of molecular species in the organ-conforming microfluidic stream was dependent on the organ preservation conditions. Enzyme-linked immunosorbent assay (ELISA) studies revealed conformal microfluidic devices isolate clinically relevant metabolic and pathophysiological biomarkers from whole organs, including heat shock protein 70 (HSP-70) and kidney injury molecule-1 (KIM-1), which were detected in the microfluidic device as high as 409 and 12 pg mL, respectively. Overall, these results show conformal microfluidic devices enable a novel minimally invasive 'microfluidic biopsy' technique for isolation and profiling of biomarkers from whole organs within a clinically relevant interval. This achievement could shift the paradigm for whole organ preservation and assessment, thereby helping to relieve the organ shortage crisis through increased availability and quality of donor organs. Ultimately, this work provides a major advance in microfluidics through the design and manufacturing of organ-conforming microfluidic devices and a novel technique for microfluidic-based analysis of whole organs.

Interfacing anatomically conformal electronic components, such as sensors, with biology is central to the creation of next-generation wearable systems for health care and human augmentation applications. Thus, there is a need to establish computer-aided design and manufacturing methods for producing personalized anatomically conformal systems, such as wearable devices and human-machine interfaces (HMIs). Here, we show that a three-dimensional (3D) scanning and 3D printing process enabled the design and fabrication of a sensor-integrated anatomical human-machine interface (AHMI) in the form of personalized prosthetic hands that contain anatomically conformal electrode arrays for children affected by amniotic band syndrome, a common birth defect. A methodology for identifying optimal scanning parameters was identified based on local and global metrics of registered point cloud data quality. This method identified an optimal rotational angle step size between adjacent 3D scans. The sensitivity of the optimization process to variations in organic shape ( i . e ., geometry) was examined by testing other anatomical structures, including a foot, an ear, and a porcine kidney. We found that personalization of the prosthetic interface increased the tissue-prosthesis contact area by 408% relative to the non-personalized devices. Conformal 3D printing of carbon nanotube-based polymer inks across the personalized AHMI facilitated the integration of electronic components, specifically, conformal sensor arrays for measuring the pressure distribution across the AHMI ( i . e ., the tissue-prosthesis interface). We found that the pressure across the AHMI exhibited a non-uniform distribution and became redistributed upon activation of the prosthetic hand’s grasping action. Overall, this work shows that the integration of 3D scanning and 3D printing processes offers the ability to design and fabricate wearable systems that contain sensor-integrated AHMIs.

The aim of this study was to characterize modified proso millet (Panicum miliaceum) starch in order to explore its prospect as an ingredient for food applications. The current study determined the effect of hydrothermal modification (HTM) at 30 g/100 g moisture level and acid modification (AM) with HCl on extracted proso millet starch physicochemical and functional properties. Amylose content reduces with AM while HTM showed negligible effect. HTM starch had higher water binding capacity (WBC) whereas AM starch showed reduction in WBC. Additionally, the solubility and swelling power of HTM starch decreased with increase in temperature, and in AM starch solubility increased sharply but swelling power increases at 80 °C but significantly (P<0.05) reduces at 90 °C. HTM caused increase in gelatinization temperature with a mean value of 87.17 °C compared to 78.61 °C in native starch. AM reduced onset (69.71 °C) and gelatinization temperature (77.26 °C), and it increased the range (26.56 °C) significantly (P <0.05) with no effect on ΔH G. Pasting profiles of native proso millet starch changed significantly (P <0.05) upon modifications and reduction in peak viscosity was observed in both modifications. AM reduced the holding strength, final viscosity, setback and breakdown whereas HTM reduced only breakdown and no change was observed in other parameters.

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Three-dimensional (3D) printing now enables the fabrication of 3D structural electronics and microfluidics. Further, conventional subtractive manufacturing processes for microelectromechanical systems (MEMS) relatively limit device structure to two dimensions and require post-processing steps for interface with microfluidics. Thus, the objective of this work is to create an additive manufacturing approach for fabrication of 3D microfluidic-based MEMS devices that enables 3D configurations of electromechanical systems and simultaneous integration of microfluidics. Here, we demonstrate the ability to fabricate microfluidic-based acoustofluidic devices that contain orthogonal out-of-plane piezoelectric sensors and actuators using additive manufacturing. The devices were fabricated using a microextrusion 3D printing system that contained integrated pick-and-place functionality. Additively assembled materials and components included 3D printed epoxy, polydimethylsiloxane (PDMS), silver nanoparticles, and eutectic gallium-indium as well as robotically embedded piezoelectric chips (lead zirconate titanate (PZT)). Electrical impedance spectroscopy and finite element modeling studies showed the embedded PZT chips exhibited multiple resonant modes of varying mode shape over the 0-20 MHz frequency range. Flow visualization studies using neutrally buoyant particles (diameter = 0.8-70 μm) confirmed the 3D printed devices generated bulk acoustic waves (BAWs) capable of size-selective manipulation, trapping, and separation of suspended particles in droplets and microchannels. Flow visualization studies in a continuous flow format showed suspended particles could be moved toward or away from the walls of microfluidic channels based on selective actuation of in-plane or out-of-plane PZT chips. This work suggests additive manufacturing potentially provides new opportunities for the design and fabrication of acoustofluidic and microfluidic devices.