Surface micromachined polysilicon heart cell force transducer

2000 ◽  
Vol 9 (1) ◽  
pp. 9-17 ◽  
Author(s):  
G. Lin ◽  
K.S.J. Pister ◽  
K.P. Roos
Keyword(s):  
Force Transducer ◽  
Heart Cell ◽  
Cell Force

Miniature heart cell force transducer system implemented in MEMS technology

2001 ◽  
Vol 48 (9) ◽  
pp. 996-1006 ◽  
Author(s):  
Gisela Lin ◽  
R.E. Palmer ◽  
K.S.J. Pister ◽  
K.P. Roos
Keyword(s):  
Force Transducer ◽  
Heart Cell ◽  
Mems Technology ◽  
Cell Force

Whole field decoupling of predistortion on polymeric cell force transducer

2011 ◽  
Vol 98 (17) ◽  
pp. 173701
Author(s):  
Xiaoyu Zheng ◽  
Xin Zhang
Keyword(s):  
Force Transducer ◽  
Cell Force

Combined force and voltage measurement in rapidly superfused guinea pig heart cells

1990 ◽  
Vol 258 (4) ◽  
pp. C739-C748 ◽  
Author(s):  
N. Shepherd ◽  
V. J. Fisher
Keyword(s):  
Membrane Potential ◽  
Guinea Pig ◽  
Isometric Force ◽  
Force Transducer ◽  
Heart Cell ◽  
Heart Cells ◽  
Voltage Measurement ◽  
Guinea Pig Heart ◽  
Control Value ◽  
Voltage Follower

We describe the construction and use of a setup that allows the rapid exchange of the solution surrounding an isolated guinea pig heart cell while simultaneously measuring the isometric force and membrane potential (Em). Cells were stably attached, by means of poly-L-lysine, to a force transducer which was adapted from one previously used for a study of frog atrial cells [N. Shepherd and F. Kavaler.Am. J. Physiol. 251 (Cell Physiol. 20): C653-C661, 1986]. The modified transducer is simple to construct and use and can be readily added to existing patch-clamp setups. The strength of attachment of a cell to the transducer exceeded the strength of the gigaseal in all of the experiments. The membrane potential was measured by means of patch electrodes and a high-impedance voltage follower. Rapidly changing extracellular K concentration [( K]o) from 5.4 to 10.8 mM caused a positive change of Em by 16.5 +/- 1.4 mV with a half-time (t1/2) of 27 +/- 4 ms. Replacing calcium in the perfusate by magnesium instantly abolished the contraction and shortened the action potential. Twitch tension returned stepwise to the control value on return of calcium to the perfusate. Our initial observations show that the patch electrode can be used successfully in conjunction with the isometric force transducer and rapid extracellular solution changes for studies of excitation and contraction coupling in isolated mammalian heart cells.

scholarly journals Development of force plate for prosthetic applications interfacing with internet of things

2018 ◽  
Vol 7 (2.7) ◽  
pp. 944
Author(s):  
Y Bharat Satya Kumar ◽  
Y Kalyan Chakravarthy ◽  
Ratna Prasad Paladagu ◽  
R Venkatesh ◽  
A Srinath
Keyword(s):  
Ground Reaction Force ◽  
Load Capacity ◽  
Reaction Force ◽  
Force Plate ◽  
Maximum Load ◽  
Force Transducer ◽  
Electrical Signal ◽  
Limb Kinematics ◽  
Cell Force ◽  
Lower Limb Kinematics

Force Plate is a measuring instrument which is used to calibrate the ground reaction force in gait cycle analysis of a subject (human or animal). Force plates are used to examine the lower limb kinematics for the applications of prosthetics, sports etc. In this study, a prototype of force plate is developed indigenously in an economical manner. It comprises of two metallic frames with a load cell (force transducer) mounted between them to produce an electrical signal as output, that is proportional to the amount of force applied on the surface of force plate. This prototype has a maximum load capacity of 3000N. The design of the force plate system along with the ground reaction force analysis and results are discussed below.  

Nano-Porous Substrates Reduce Beetle Attachment Force

2008 ◽  
Author(s):  
E. Gorb ◽  
N. Hosoda ◽  
S. Gorb
Keyword(s):  
Force Measurement ◽  
Glass Plate ◽  
Coccinella Septempunctata ◽  
Traction Force ◽  
Force Transducer ◽  
Back Side ◽  
Force Measurements ◽  
Cell Force ◽  
Insect Attachment ◽  
Porous Substrates

Traction experiments with the seven-spotted ladybird beetles Coccinella septempunctata (L.) (Coleoptera, Coccinellidae) were carried out to study the influence of surface structure on insect attachment. Force measurements were performed with tethered walking insects using a load cell force transducer. For each beetle, forces were measured on five different substrates: (1) smooth glass plate; (2) smooth solid Al2O3 (sapphire) disc; (3 – 5) porous Al2O3 discs (anodiscs, back side) with the same pore diameter (220 – 235 nm), but different porosity (28, 42 and 51%). Males (N = 10) and females (N = 10) were used in experiments (10 single runs on each surface). Additionally, inversion tests were performed after each traction force measurement. The force ranged from 0.368 to 10.370 mN in males and from 0.514 to 6.262 mN in females. In both sexes, the highest force values were obtained on the smooth glass and sapphire surfaces, where males generated considerably higher forces compared to females. On all three porous substrates, forces were significantly reduced in both males and females, and the only difference for surfaces was obtained between two extremes: anodiscs with the highest (51%) and lowest (28%) porosity. Males produced essentially lower forces than females on anodiscs samples. Experimental insects performed well and showed normal locomotion on both smooth surfaces. On all anodiscs samples, beetles usually were not able to get a grip and slid over the surface, refused to walk and came to a standstill or even turned over on their backs. When substrates were inverted to 90° and 180°, insects were still able to remain attached to both the glass and sapphire samples, but failed on anodiscs. The reduction of insect attachment on anodiscs surfaces is explained by (1) possible absorption of the secretory fluid from insect pads by porous media and (2) effect of surface roughness.

Roughness-dependent friction force of the tarsal claw system in the beetlePachnoda marginata(Coleoptera, Scarabaeidae)

2002 ◽  
Vol 205 (16) ◽  
pp. 2479-2488 ◽  
Author(s):  
Zhendong Dai ◽  
Stanislav N. Gorb ◽  
Uli Schwarz
Keyword(s):  
Surface Roughness ◽  
Friction Force ◽  
Relative Size ◽  
Particle Diameter ◽  
Force Transducer ◽  
Average Particle ◽  
Substrate Texture ◽  
Surface Irregularities ◽  
Force Range ◽  
Cell Force

SUMMARYThis paper studies slide-resisting forces generated by claws in the free-walking beetle Pachnoda marginata (Coleoptera, Scarabaeoidea)with emphasis on the relationship between the dimension of the claw tip and the substrate texture. To evaluate the force range by which the claw can interact with a substrate, forces generated by the freely moving legs were measured using a load cell force transducer. To obtain information about material properties of the claw, its mechanical strength was tested in a fracture experiment, and the internal structure of the fractured claw material was studied by scanning electron microscopy. The bending stress of the claw was evaluated as 143.4-684.2 MPa, depending on the cross-section model selected. Data from these different approaches led us to propose a model explaining the saturation of friction force with increased texture roughness. The forces are determined by the relative size of the surface roughness Ra (or an average particle diameter) and the diameter of the claw tip. When surface roughness is much bigger than the claw tip diameter, the beetle can grasp surface irregularities and generate a high degree of attachment due to mechanical interlocking with substrate texture. When Ra is lower than or comparable to the claw tip diameter, the frictional properties of the contact between claw and substrate particles play a key role in the generation of the friction force.

Heart cell contractions measured using a micromachined polysilicon force transducer

1995 ◽  
Author(s):  
Gisela Lin ◽  
Kristofer S. J. Pister ◽  
Kenneth P. Roos
Keyword(s):  
Force Transducer ◽  
Heart Cell
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