PMID- 33022596
OWN - NLM
STAT- MEDLINE
DCOM- 20210219
LR  - 20230509
IS  - 2470-9476 (Electronic)
IS  - 2470-9476 (Linking)
VI  - 5
IP  - 38
DP  - 2020 Jan 29
TI  - Autonomic perspiration in 3D-printed hydrogel actuators.
LID - eaaz3918 [pii]
LID - 10.1126/scirobotics.aaz3918 [doi]
AB  - In both biological and engineered systems, functioning at peak power output for 
      prolonged periods of time requires thermoregulation. Here, we report a soft 
      hydrogel-based actuator that can maintain stable body temperatures via autonomic 
      perspiration. Using multimaterial stereolithography, we three-dimensionally print 
      finger-like fluidic elastomer actuators having a poly-N-isopropylacrylamide 
      (PNIPAm) body capped with a microporous (~200 micrometers) polyacrylamide (PAAm) 
      dorsal layer. The chemomechanical response of these hydrogel materials is such 
      that, at low temperatures (<30 degrees C), the pores are sufficiently closed to allow for 
      pressurization and actuation, whereas at elevated temperatures (>30 degrees C), the pores 
      dilate to enable localized perspiration in the hydraulic actuator. Such sweating 
      actuators exhibit a 600% enhancement in cooling rate (i.e., 39.1 degrees C minute(-1)) 
      over similar non-sweating devices. Combining multiple finger actuators into a 
      single device yields soft robotic grippers capable of both mechanically and 
      thermally manipulating various heated objects. The measured thermoregulatory 
      performance of these sweating actuators (~107 watts kilogram(-1)) greatly exceeds 
      the evaporative cooling capacity found in the best animal systems (~35 watts 
      kilogram(-1)) at the cost of a temporary decrease in actuation efficiency.
CI  - Copyright (c) 2020 The Authors, some rights reserved; exclusive licensee American 
      Association for the Advancement of Science. No claim to original U.S. Government 
      Works.
FAU - Mishra, Anand K
AU  - Mishra AK
AUID- ORCID: 0000-0001-7423-7850
AD  - Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, 
      NY 14850, USA.
FAU - Wallin, Thomas J
AU  - Wallin TJ
AUID- ORCID: 0000-0002-7867-0114
AD  - Facebook Reality Labs, Redmond, WA 98052, USA.
AD  - Department of Materials Science and Engineering, Cornell University, Ithaca, NY 
      14850, USA.
FAU - Pan, Wenyang
AU  - Pan W
AUID- ORCID: 0000-0002-0723-6943
AD  - Department of Materials Science and Engineering, Cornell University, Ithaca, NY 
      14850, USA.
FAU - Xu, Artemis
AU  - Xu A
AUID- ORCID: 0000-0002-4576-742X
AD  - Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, 
      NY 14850, USA.
FAU - Wang, Kaiyang
AU  - Wang K
AUID- ORCID: 0000-0002-1529-0958
AD  - Department of Materials Science and Engineering, Cornell University, Ithaca, NY 
      14850, USA.
FAU - Giannelis, Emmanuel P
AU  - Giannelis EP
AD  - Department of Materials Science and Engineering, Cornell University, Ithaca, NY 
      14850, USA.
FAU - Mazzolai, Barbara
AU  - Mazzolai B
AUID- ORCID: 0000-0003-0722-8350
AD  - Center for Micro-Biorobotics, Istituto Italiano di Technologia, Pontedera, PI 
      56025 Pisa, Italy.
FAU - Shepherd, Robert F
AU  - Shepherd RF
AUID- ORCID: 0000-0002-0631-9587
AD  - Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, 
      NY 14850, USA. rfs247@cornell.edu.
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Sci Robot
JT  - Science robotics
JID - 101733136
RN  - 0 (Acrylic Resins)
RN  - 0 (Elastomers)
RN  - 0 (Hydrogels)
RN  - 25189-55-3 (poly-N-isopropylacrylamide)
RN  - 9003-05-8 (polyacrylamide)
SB  - IM
MH  - Acrylic Resins
MH  - Animals
MH  - Autonomic Nervous System/physiology
MH  - *Biomimetic Materials
MH  - Biomimetics
MH  - Body Temperature Regulation/physiology
MH  - Elastomers
MH  - Equipment Design
MH  - Hydrogels
MH  - Models, Biological
MH  - Porosity
MH  - *Printing, Three-Dimensional
MH  - Rheology
MH  - Robotics/*instrumentation
MH  - Sweating/*physiology
EDAT- 2020/10/07 06:00
MHDA- 2021/02/20 06:00
CRDT- 2020/10/06 20:17
PHST- 2019/09/05 00:00 [received]
PHST- 2019/12/17 00:00 [accepted]
PHST- 2020/10/06 20:17 [entrez]
PHST- 2020/10/07 06:00 [pubmed]
PHST- 2021/02/20 06:00 [medline]
AID - 5/38/eaaz3918 [pii]
AID - 10.1126/scirobotics.aaz3918 [doi]
PST - ppublish
SO  - Sci Robot. 2020 Jan 29;5(38):eaaz3918. doi: 10.1126/scirobotics.aaz3918.