PMID- 36317698
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20221116
IS  - 1744-6848 (Electronic)
IS  - 1744-683X (Linking)
VI  - 18
IP  - 44
DP  - 2022 Nov 16
TI  - Effects of AC frequency on the capacitance measurement of hybrid response 
      pressure sensors.
PG  - 8476-8485
LID - 10.1039/d2sm01250b [doi]
AB  - E-skins consisting of soft pressure sensors are enabling technology for soft 
      robots, bio-integrated devices, and deformable touch panels. A well-known 
      bottleneck of capacitive pressure sensors (CPS) is the drastic decay in 
      sensitivity with increasing pressure. To overcome this challenge, we have 
      invented a hybrid-response pressure sensor (HRPS) that exhibits both the 
      piezoresistive and piezocapacitive effects intrinsic to a highly porous 
      nanocomposite (PNC) with carbon nanotube (CNT) dopants. The HRPS is constructed 
      with two conductive electrodes sandwiching a laminated PNC and a stiff dielectric 
      layer. We have simplified the hybrid response into a parallel resistor-capacitor 
      circuit, whose output depends on the AC (alternating current) frequency used for 
      the capacitance measurement. Herein, through theoretical analysis, we discover a 
      dimensionless parameter that governs the frequency responses of the HRPS. The 
      master curve is validated through experiments on the HRPS with various doping 
      ratios, subject to different compressive strains, under diverse AC frequencies. 
      In addition, the relative contribution of piezoresistive and piezocapacitive 
      mechanisms are also found to vary with the three parameters. Based on this 
      experimentally validated theory, we establish a very practical guideline for 
      selecting the optimal AC frequency for the capacitance measurement of HRPSs.
FAU - Li, Zhengjie
AU  - Li Z
AUID- ORCID: 0000-0002-2918-2800
AD  - Department of Aerospace Engineering and Engineering Mechanics, the University of 
      Texas at Austin, TX, 78712, USA. nanshulu@utexas.edu.
FAU - Ha, Kyoung-Ho
AU  - Ha KH
AD  - Department of Mechanical Engineering, the University of Texas at Austin, TX, 
      78712, USA.
FAU - Wang, Zheliang
AU  - Wang Z
AD  - Department of Aerospace Engineering and Engineering Mechanics, the University of 
      Texas at Austin, TX, 78712, USA. nanshulu@utexas.edu.
FAU - Kim, Sangjun
AU  - Kim S
AD  - Department of Mechanical Engineering, the University of Texas at Austin, TX, 
      78712, USA.
FAU - Davis, Ben
AU  - Davis B
AD  - Department of Mechanical Engineering, the University of Texas at Austin, TX, 
      78712, USA.
FAU - Lu, Ruojun
AU  - Lu R
AD  - Department of Mechanical Engineering, the University of Texas at Austin, TX, 
      78712, USA.
FAU - Sirohi, Jayant
AU  - Sirohi J
AUID- ORCID: 0000-0001-7978-2882
AD  - Department of Aerospace Engineering and Engineering Mechanics, the University of 
      Texas at Austin, TX, 78712, USA. nanshulu@utexas.edu.
FAU - Lu, Nanshu
AU  - Lu N
AD  - Department of Aerospace Engineering and Engineering Mechanics, the University of 
      Texas at Austin, TX, 78712, USA. nanshulu@utexas.edu.
AD  - Department of Mechanical Engineering, the University of Texas at Austin, TX, 
      78712, USA.
AD  - Department of Biomedical Engineering, the University of Texas at Austin, TX, 
      78712, USA.
AD  - Department of Electrical and Computer Engineering, the University of Texas at 
      Austin, TX, 78712, USA.
LA  - eng
PT  - Journal Article
DEP - 20221116
PL  - England
TA  - Soft Matter
JT  - Soft matter
JID - 101295070
SB  - IM
EDAT- 2022/11/02 06:00
MHDA- 2022/11/02 06:01
CRDT- 2022/11/01 07:02
PHST- 2022/11/02 06:00 [pubmed]
PHST- 2022/11/02 06:01 [medline]
PHST- 2022/11/01 07:02 [entrez]
AID - 10.1039/d2sm01250b [doi]
PST - epublish
SO  - Soft Matter. 2022 Nov 16;18(44):8476-8485. doi: 10.1039/d2sm01250b.