skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Extrusion-based 3D printing of soft active materials
This feature article summarizes recent advances in extrusion-based 3D printing of active materials in both non-living and living systems.  more » « less
Award ID(s):
2011924
PAR ID:
10589205
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
RSC
Date Published:
Journal Name:
Chemical Communications
Volume:
60
Issue:
58
ISSN:
1359-7345
Page Range / eLocation ID:
7414 to 7426
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract Living biological systems, ranging from single cells to whole organisms, can sense, process information, and actuate in response to changing environmental conditions. Inspired by living biological systems, engineered living cells and nonliving matrices are brought together, which gives rise to the technology of engineered living materials. By designing the functionalities of living cells and the structures of nonliving matrices, engineered living materials can be created to detect variability in the surrounding environment and to adjust their functions accordingly, thereby enabling applications in health monitoring, disease treatment, and environmental remediation. Hydrogels, a class of soft, wet, and biocompatible materials, have been widely used as matrices for engineered living cells, leading to the nascent field of engineered living hydrogels. Here, the interactions between hydrogel matrices and engineered living cells are described, focusing on how hydrogels influence cell behaviors and how cells affect hydrogel properties. The interactions between engineered living hydrogels and their environments, and how these interactions enable versatile applications, are also discussed. Finally, current challenges facing the field of engineered living hydrogels for their applications in clinical and environmental settings are highlighted. 
    more » « less
  2. Abstract Living creatures are continuous sources of inspiration for designing synthetic materials. However, living creatures are typically different from synthetic materials because the former consist of living cells to support their growth and regeneration. Although natural systems can grow materials with sophisticated microstructures, how to harness living cells to grow materials with predesigned microstructures in engineering systems remains largely elusive. Here, an attempt to exploit living bacteria and 3D‐printed materials to grow bionic mineralized composites with ordered microstructures is reported. The bionic composites exhibit outstanding specific strength and fracture toughness, which are comparable to natural composites, and exceptional energy absorption capability superior to both natural and artificial counterparts. This report opens the door for 3D‐architectured hybrid synthetic–living materials with living ordered microstructures and exceptional properties. 
    more » « less
  3. Abstract When plants die, neighbours escape competition. Living conspecifics could disproportionately benefit because they are freed from negative intraspecific processes; however, if the negative effects of past conspecific neighbours persist, other species might be advantaged, and diversity might be maintained through legacy effects. We examined legacy effects in a mapped forest by modelling the survival of 37,212 trees of 23 species using four neighbourhood properties: living conspecific, living heterospecific, legacy conspecific (dead conspecifics) and legacy heterospecific densities. Legacy conspecific effects proved nearly four times stronger than living conspecific effects; changes in annual survival associated with legacy conspecific density were 1.5% greater than living conspecific effects. Over 90% of species were negatively impacted by legacy conspecific density, compared to 47% by living conspecific density. Our results emphasize that legacies of trees alter community dynamics, revealing that prior research may have underestimated the strength of density dependent interactions by not considering legacy effects. 
    more » « less
  4. BackgroundLiving kidney donation currently constitutes approximately a quarter of all kidney donations. There exist barriers that preclude prospective donors from donating, such as medical ineligibility and costs associated with donation. A better understanding of perceptions of and barriers to living donation could facilitate the development of effective policies, education opportunities, and outreach strategies and may lead to an increased number of living kidney donations. Prior research focused predominantly on perceptions and barriers among a small subset of individuals who had prior exposure to the donation process. The viewpoints of the general public have rarely been represented in prior research. ObjectiveThe current study designed a web-scraping method and machine learning algorithms for collecting and classifying comments from a variety of online sources. The resultant data set was made available in the public domain to facilitate further investigation of this topic. MethodsWe collected comments using Python-based web-scraping tools from the New York Times, YouTube, Twitter, and Reddit. We developed a set of guidelines for the creation of training data and manual classification of comments as either related to living organ donation or not. We then classified the remaining comments using deep learning. ResultsA total of 203,219 unique comments were collected from the above sources. The deep neural network model had 84% accuracy in testing data. Further validation of predictions found an actual accuracy of 63%. The final database contained 11,027 comments classified as being related to living kidney donation. ConclusionsThe current study lays the groundwork for more comprehensive analyses of perceptions, myths, and feelings about living kidney donation. Web-scraping and machine learning classifiers are effective methods to collect and examine opinions held by the general public on living kidney donation. 
    more » « less
  5. Abstract Living materials are created through the embedding of live, whole cells into a matrix that can house and sustain the viability of the encapsulated cells. Through the immobilization of these cells, their bioactivity can be harnessed for applications such as bioreactors for the production of high‐value chemicals. While the interest in living materials is growing, many existing materials lack robust structure and are difficult to pattern. Furthermore, many living materials employ only one type of microorganism, or microbial consortia with little control over the arrangement of the various cell types. In this work, a Pluronic F127‐based hydrogel system is characterized for the encapsulation of algae, yeast, and bacteria to create living materials. This hydrogel system is also demonstrated to be an excellent material for additive manufacturing in the form of direct write 3D‐printing to spatially arrange the cells within a single printed construct. These living materials allow for the development of incredibly complex, immobilized consortia, and the results detailed herein further enhance the understanding of how cells behave within living material matrices. The utilization of these materials allows for interesting applications of multikingdom microbial cultures in immobilized bioreactor or biosensing technologies. 
    more » « less