Publications by authors named "Jun-Chang Yang"

3D printing technologies have been widely used for the rapid prototyping of 3D structures, but their application in a broader context has been hampered by their low printing throughput. For the same structures to be produced in a variety of sizes and materials, each must be printed separately, which increases time and cost. Replicating 3D-printed structures in a variety of sizes using a molding process with size-tunable molds could be a solution, but it has only been applied to simple structures, such as those with tapered or vertical profiles.

View Article and Find Full Text PDF

Thermal homeostasis is an essential physiological function for preserving the optimal state of complex organs within the human body. Inspired by this function, here, we introduce an autonomous thermal homeostatic hydrogel that includes infrared wave reflecting and absorbing materials for improved heat trapping at low temperatures, and a porous structure for enhanced evaporative cooling at high temperatures. Moreover, an optimized auxetic pattern was designed as a heat valve to further amplify heat release at high temperatures.

View Article and Find Full Text PDF

A soft bending sensor based on the inverse pyramid structure is demonstrated, revealing that it can effectively suppress microcrack formation in designated regions, thus allowing the cracks to open gradually with bending in a controlled manner. Such a feature enabled the bending sensor to simultaneously have a wide dynamic range of bending strain (0.025-5.

View Article and Find Full Text PDF

Integration of rigid components in soft polymer matrix is considered as the most feasible architecture to enable stretchable electronics. However, a method of suppressing cracks at the interface between soft and rigid materials due to excessive and repetitive deformations of various types remains a formidable challenge. Here, we geometrically engineered Ferris wheel-shaped islands (FWIs) capable of effectively suppressing crack propagation at the interface under various deformation modes (stretching, twisting, poking, and crumpling).

View Article and Find Full Text PDF

Hybridization of low-dimensional components with diverse geometrical dimensions should offer an opportunity for the discovery of synergistic nanocomposite structures. In this regard, how to establish a reliable interfacial interaction is the key requirement for the successful integration of geometrically different components. Here, we present 1D/2D heterodimensional hybrids via dopant induced hybridization of 2D TiCT MXene with 1D nitrogen-doped graphene nanoribbon.

View Article and Find Full Text PDF

Passive component-based soft resonators have been spotlighted in the field of wearable and implantable devices due to their remote operation capability and tunable properties. As the output signal of the resonator-based wireless communication device is given in the form of a vector (, a spectrum of reflection coefficient), multiple information can, in principle, be stored and interpreted. Herein, we introduce a device that can deconvolute mechanical stimuli from a single wireless signal using dual-mode operation, specifically enabled by the use of TiCT MXene.

View Article and Find Full Text PDF

To mimic the tactile sensing properties of the human skin, signals from tactile sensors need to be processed in an efficient manner. The integration of the tactile sensor with a neuromorphic device can potentially address this issue, as the neuromorphic device has both signal processing and memory capability through which parallel and efficient processing of information is possible. In this article, an intelligent haptic perception device (IHPD) is presented that combines pressure sensing with an organic electrochemical transistor-based synaptic device into a simple device architecture.

View Article and Find Full Text PDF

The demand for display technology is expected to increase with the continuous spread of portable electronics and with the expected emergence of flexible, wearable, and transparent display devices. A touch screen is a critical component in display technology that enables user interface operations, and the future generation of touch screens, the so-called 3D touch screens, is expected to be able to detect multiple levels of pressure. To enable 3D touch screens, transparent pressure sensors with high linearity over a working range that encompasses the pressure range of human touch (10-100 kPa) are required.

View Article and Find Full Text PDF

Inspired by the human somatosensory system, pressure applied to multiple pressure sensors is received in parallel and combined into a representative signal pattern, which is subsequently processed using machine learning. The pressure signals are combined using a wireless system, where each sensor is assigned a specific resonant frequency on the reflection coefficient (S ) spectrum, and the applied pressure changes the magnitude of the S pole with minimal frequency shift. This allows the differentiation and identification of the pressure applied to each sensor.

View Article and Find Full Text PDF

Recent progress in electronic skin or e-skin research is broadly reviewed, focusing on technologies needed in three main applications: skin-attachable electronics, robotics, and prosthetics. First, since e-skin will be exposed to prolonged stresses of various kinds and needs to be conformally adhered to irregularly shaped surfaces, materials with intrinsic stretchability and self-healing properties are of great importance. Second, tactile sensing capability such as the detection of pressure, strain, slip, force vector, and temperature are important for health monitoring in skin attachable devices, and to enable object manipulation and detection of surrounding environment for robotics and prosthetics.

View Article and Find Full Text PDF

Sensor-to-sensor variability and high hysteresis of composite-based piezoresistive pressure sensors are two critical issues that need to be solved to enable their practical applicability. In this work, a piezoresistive pressure sensor composed of an elastomer template with uniformly sized and arranged pores, and a chemically grafted conductive polymer film on the surface of the pores is presented. Compared to sensors composed of randomly sized pores, which had a coefficient of variation (CV) in relative resistance change of 69.

View Article and Find Full Text PDF

An ultrahigh sensitive capacitive pressure sensor based on a porous pyramid dielectric layer (PPDL) is reported. Compared to that of the conventional pyramid dielectric layer, the sensitivity was drastically increased to 44.5 kPa in the pressure range <100 Pa, an unprecedented sensitivity for capacitive pressure sensors.

View Article and Find Full Text PDF

Electronic skin are devices that mimic the functionalities of human skin, which require high sensitivity, large dynamic range, high spatial uniformity, low-cost and large-area processability, and the capacity to differentiate various external inputs. We herein introduce a versatile droplet-based microfluidic-assisted emulsion self-assembly process to generate three-dimensional microstructure-based high-performance capacitive and piezoresistive pressure sensors for electronic skin applications. Our technique can generate uniformly sized micropores that are self-assembled in an orderly close-packed manner over a large area, which results in high spatial uniformity.

View Article and Find Full Text PDF

Tactile sensors that can mechanically decouple, and therefore differentiate, various tactile inputs are highly important to properly mimic the sensing capabilities of human skin. Herein, we present an all-solution processable pressure insensitive strain sensor that utilizes the difference in structural change upon the application of pressure and tensile strain. Under the application of strain, microcracks occur within the multiwalled carbon nanotube (MWCNT) network, inducing a large change in resistance with gauge factor of ∼56 at 70% strain.

View Article and Find Full Text PDF

Objective: To investigate the feasibility, effectiveness and practicability of transurethral enucleation plus pneumocystostomy rotary cut (TUE + PCRC) for large benign prostatic hyperplasia (BPH).

Methods: We performed TUE + PCRC for 26 BPH patients aged 62 - 85 years with the prostate volume of 80 - 165 ml. We conducted transurethral enucleation of the hyperplastic prostate glands and pushed them into the bladder, followed by bladder puncture for pneumo-cystostomy rotary cut.

View Article and Find Full Text PDF

Objective: To evaluate endourethral surgery for urethratresia under the X-ray guide.

Methods: We performed transurethral urethroplasty for 11 patients with urethratresia using the PlasmaKinetic electrodes under the guidance of C arm xanthippe.

Results: In the 11 cases, operations were all successful, 9 achieved smooth urination and 2 needed regular urethral dilation.

View Article and Find Full Text PDF