The Hong Kong Polytechnic University

Chen Chao

Ching-Hsiang Cheng

Yin-Nee Cheung

Helen Lai Wa Chan

Helen L W Chan

Kin Wing Kwok

Ching Hsiang Cheng

Yin Nee Cheung

Jue Peng

Tin Yan Lam

Ji-yan Dai

Yun Zhu

The present invention relates a method of fabricating a piezoelectric device through micromachining piezoelectric-on-silicon wafer. The wafers are constructed so that piezoelectric layer is a single wafer having a thin layer from 5 to 50 &#x3bc;m.

Fabrication of piezoelectric single crystalline thin layer on silicon wafer

A Capacitive Micromachined Ultrasonic Transducer (CMUT) having a membrane operatively connected to a top electrode and having a bottom electrode having a concave void. When a DC bias voltage is applied, the membrane is deflected towards the bottom electrode such that a peripheral edge region of the membrane is brought into close proximity with the bottom electrode and an electrostatic force proximal to the peripheral edge region of the membrane is increased.

Flexible capacitive micromachined ultrasonic transducer array with increased effective capacitance

The present invention relates to a microvalve having a valve plug, connecting legs, anchors and actuators, allowing the valve plug to move vertically to open or close the valve. The valve plug can contain magnetic materials, and be operated by an actuator.

Polymer microvalve with actuators and devices

A strain sensor () for measuring strain greater than 10%, the sensor () comprising: an upper polydimethylsiloxane (PDMS) substrate () having measurement electrodes () extending therethrough; a lower PDMS substrate () bonded to a lower surface of the upper PDMS substrate (), and an upper surface of the lower PDMS substrate () having a patterned portion (); and a conductive fluid () contained within the patterned portion () in contact with the measurement electrodes ().

Strain sensor

An apparatus and method for detecting the oscillation amplitude of a bonding tool includes a sensing unit disposed adjacent to and at a distance from the bonding tool. The sensing unit includes a pair of electrodes, a piezoelectric sensing layer located between the pair of electrodes, and a membrane associated with the piezoelectric sensing layer. The piezoelectric sensing layer becomes sensitive to ultrasonic vibrations and generates electrical voltage signals after being activated by a poling process. An optional pre-amplifier is used to amplify the signals generated from the sensing unit, and an oscilloscope is used to further process the signals.

Method and apparatus for measuring oscillation amplitude of an ultrasonic device

A force sensor includes a polymeric substrate including a cavity with a tilt plane, at least two metal piezoresistors on the tilt plane, and a contact pad connected to the metal piezoresistors. The tilt plane may include a measured interface of from 15&#xb0; to 75&#xb0;.

Flexible piezoresistive interfacial shear and normal force sensor and sensor array

The present invention relates to a strain gauge having a conductive fluid made of a glycerin/aqueous salt mixture, and methods of making the strain gauge. The strain gauge is capable of measuring large displacement of around 30% true strain.

Fluidic piezoresistive strain gauge

The present invention relates to a strain gauge and methods of making such wherein the gauge contains a doped polymeric fluid suitable for measuring elongations of more than 10%.

Growing community of inventors

Hong Kong, China

Chen Chao