Open AccessThree‐axis capacitive force sensor with liquid metal electrodes for endoscopic palpation
Author(s) -
Nagatomo Tatsuho,
Miki Norihisa
Publication year - 2017
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2017.0135
Subject(s) - capacitive sensing , palpation , endoscope , materials science , electrode , biomedical engineering , liquid metal , tactile sensor , acoustics , optoelectronics , computer science , electrical engineering , radiology , composite material , artificial intelligence , engineering , medicine , physics , quantum mechanics , robot
Endoscopic palpation is a promising technology for detecting tumours that are too small to be detected by CT and magnetic resonance imaging, are not located on tissue surfaces, and cannot be observed using endoscopes. This method uses a small force sensor mounted on the tip of an endoscope. It is desirable that the sensor can scan tissue surfaces and continuously measure the stiffness of organs. Prior work developed a ballpoint‐pen‐like capacitive force sensor and carried out proof of principle experiments; however, the sensor was too large to be mounted on an endoscope. This study designed three‐dimensional (3D) microfluidic channels encapsulating liquid metal to develop a sensor that is small enough to be mounted on an endoscope. Eight polydimethyl siloxane layers with channel structures were assembled and filled with Galinstan, a commercial liquid metal, to form 3D electrodes. The sensor was experimentally characterised and verified to be applicable to endoscopic palpation.