Publications by Christian Köchli

Related publications (25)

Modeling and experimental study of a miniaturized magnetorheological valve with high performance

Yves Perriard, Christian Köchli, Sofia Lydia Ntella

Magnetorheological (MR) valves attracted the interest of researchers across diverse fields, owing to the controllable nature of MR fluid. The use of MR fluid in valves enables fast response, energy efficiency, and robustness, while several studies designed ...

Sage Publications Ltd2024

Highly Efficient Miniaturized Magnetorheological Valves Using Electropermanent Magnets

Yves Perriard, Christian Köchli, Adrien Jean-Michel Thabuis, Sofia Lydia Ntella, Bhawnath Tiwari, Kenny Jeanmonod

Fluidic systems enable actuation in various applications, such as automotive, medical, and industrial robotics. Miniaturized valves constitute a fundamental controlling element of modern fluidic systems, intriguing the interest of many researchers. This le ...

2023

Microfluidic device for analysis of magnetorheological fluids' properties

Yves Perriard, Christian Köchli, Sofia Lydia Ntella, Pooneh Mohaghegh

The valve mode is the most common operational mode of magnetorheological fluid (MRF) devices in engineering applications. Magnetorheological (MR) valves have been studied upon their self-sensing capabilities resulting from the electromagnetic induction phe ...

IEEE2022

Analytical Model for Slotless Permanent Magnet Axial Flux Motors

Yves Perriard, Christian Köchli

Permanent magnet axial flux motors are very well adapted to applications requiring a very short active length and a big diameter. They also have been used for micro-motors. Because of their size, these motors require the use of a permanent magnet and their ...

IEEE2013

Geometrically Balanced Metal Detector Based on Optimized Frequencies and Spatial Phase Profile Responses to Discriminate Different Metal Rods Features

Yves Perriard, Christian Köchli, Chafic Abu Antoun

Inductive detection with double-balanced coils and a spatial phase profile were used to identify copper and steel rods in a composite target. The electromagnetic detection system was designed and validated using a dipole model. Simulations and experiments ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Intelligent plantar pressure offloading for the prevention of diabetic foot ulcers and amputations

Yves Perriard, Yoan René Cyrille Civet, Christian Köchli, Sofia Lydia Ntella, Bhawnath Tiwari, Kenny Jeanmonod

The high prevalence of lower extremity ulceration and amputation in people with diabetes is strongly linked to difficulties in achieving and maintaining a reduction of high plantar pressures (PPs) which remains an important risk factor. The effectiveness o ...

2023

A Tunable Self-Offloading Module for Plantar Pressure Regulation in Diabetic Patients

Yves Perriard, Yoan René Cyrille Civet, Paolo Germano, Christian Köchli, Sofia Lydia Ntella, Bhawnath Tiwari, Kenny Jeanmonod

Plantar pressure plays a crucial role in the pathogenesis of foot ulcers among patients with diabetes and peripheral polyneuropathy. Pressure relief is a key requirement for both the prevention and treatment of plantar ulcers. Conventional medical practice ...

2024

Electrostatically actuated MEMs relay for high power applications

Yves Perriard, Christian Köchli, Florian Louis Copt

In this paper, a MEMs relay for high power application is investigated. This relay has to hold a current of the order of magnitude of the Ampere and is subject to harsh environment such as high temperature or vibrations which can lead to a premature dysfun ...

2016

Development of a Hybrid MEMS BLDC Micromotor

Yves Perriard, Christian Köchli, Sebastiano Merzaghi

This paper addresses the design of a new hybrid MEMS micromotor. It is a small 3-phases axial flux BLDC motor. The stator is realized following the almost CMOS technology rules used for MEMS manufacture and the coils have two copper layers. The rotor is ma ...

2009

Development of a Hybrid MEMS BLDC Micromotor

Yves Perriard, Christian Köchli, Sebastiano Merzaghi

This paper addresses the design of a new hybrid microelectromechanical systems (MEMS) micromotor. It is a small three-phase axial flux brushless dc (BLDC) motor. The stator is developed following the almost-standard CMOS technology rules used for MEMS manu ...

Institute of Electrical and Electronics Engineers2011

Validity Tests of Superposition Principle Based on Forward Model for Electromagnetic Induction Scattering

Yves Perriard, Christian Köchli, Chafic Abu Antoun

Low-frequency electromagnetic scattering from conductive and permeable bodies is the main principle of detection devices. To be able to classify the objects in the base material, a fast forward model based on the dipolar approximation was developed and ver ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Magnetorheological valve

Yves Perriard, Christian Köchli, Adrien Jean-Michel Thabuis, Sofia Lydia Ntella, Bhawnath Tiwari, Kenny Jeanmonod

The present invention relates to a valve (10) comprising a housing (11) having a peripheral structure (12) made of a magnetic field conductive material and a core (13) disposed in said housing (11) The core (13) and the peripheral structure (12) delimit a ...

2024

Validation by Measurements of a Windage Losses Model for Very-High-Speed Machines

Yves Perriard, Christian Köchli, Douglas Martins Araujo, Guillaume Paul-André Burnand

When designing a very-high-speed (VHS) machine, it is crucial to evaluate the windage losses accurately, because they are an important part of the total losses. It is therefore important to validate a reliable model, further used for the design and optimiz ...

2017

Pressure Offloading Device for Diabetic Footwear Based on Magnetorheological Fluids

Yves Perriard, Yoan René Cyrille Civet, Christian Köchli, Sofia Lydia Ntella, Kenny Jeanmonod

Diabetes is a rapidly growing disease, with important complications that decrease the quality of life of patients. Diabetic Foot Ulceration is a major complication of diabetes and can lead to gangrene and amputation. It is related to high pressure develope ...

IEEE2022

A Polyester–Nylon Blend Plantar Pressure Sensing Insole for Person With Diabetes

Yves Perriard, Yoan René Cyrille Civet, Paolo Germano, Christian Köchli, Sofia Lydia Ntella, Bhawnath Tiwari, Kenny Jeanmonod

Peripheral sensorimotor neuropathy among people with diabetes is one of the leading causes of foot ulceration. Plantar pressure is a significant parameter to control for the prevention of foot ulceration. A low-cost sensing insole, which can provide a reli ...

2023

Frequency Analysis of Finite Steel Cylinders and their Comparison to Complex Cylinder-like Targets using an Electromagnetic Induction Sensor

Yves Perriard, Christian Köchli, Chafic Abu Antoun

This paper shows that the standard industrial targets that need to be detected using an electromagnetic induction sensor cannot be represented by their exact size definition in international standards. Reinforcing steel with defined 16mm diameter according ...

IEEE2015

Preliminary Study of Pressure Self-Sensing Miniature Magnetorheological Valves

Yves Perriard, Yoan René Cyrille Civet, Christian Köchli, Sofia Lydia Ntella, Kenny Jeanmonod, Minh Trung Duöng

Magnetorheological (MR) valves have been included in many innovative engineering systems, such as dampers, clutches, or brakes, with different fields of application. Their role serves actuation purposes, while integrated displacement and velocity sensing i ...

IEEE2021

Analytical Modeling of the Flux Density in Permanent Magnet Motor

Yves Perriard, Christian Köchli

2008

Design and Manufacturing of an Electrostatic MEMS Relay for High Power Applications

Yves Perriard, Yoan René Cyrille Civet, Christian Köchli, Florian Louis Copt

This paper addresses the design and manufacturing of a crab-leg based MEMS relay for a high power application. Thanks to a contact resistance lower than 100 mΩ, the relay can hold a current in the order of magnitude of an Ampere without further thermal lim ...

2021

Valve comprising a body and a mobile piston

Yves Perriard, Yoan René Cyrille Civet, Paolo Germano, Christian Köchli, Sofia Lydia Ntella, Bhawnath Tiwari

The invention concerns a valve comprising a body (11) and a piston (12) movable in the body (11) between two extreme positions. One of the extreme positions is a so-called rest position or closed position and another extreme position is a so-called active ...

2024