Actuating Compact Augmented Reality Devices by Artificial Muscle

2021 ◽  
Author(s):  
Dongjin Kim ◽  
Baekgyeom Kim ◽  
Bongsu Shin ◽  
Dongwook Shin ◽  
Chang-Kun Lee ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Power Density ◽  
High Power ◽  
Artificial Muscle ◽  
Small Scale ◽  
High Power Density ◽  
Electromagnetic Actuators ◽  
Practical Engineering ◽  
Tactile Response ◽  
Actuation Strain

Abstract An artificial muscle actuator resolves practical engineering problems in compact wearable devices, which are limited to conventional actuators such as electromagnetic actuators. Abstracting the fundamental advantages of an artificial muscle actuator provides a small-scale, high-power actuating system for developing varifocal augmented reality (AR) glasses and naturally fit haptic gloves. Here, we design a shape memory alloy (SMA)-based lightweight and high-power artificial muscle actuator, the so-called compliant amplified SMA actuator (CASA). Despite its light weight (0.22 g), the CASA has a high power density of 1.7 kW/kg and an actuation strain of 300%. We show how CASA enables image depth control and an immersive tactile response in the form of AR glasses and haptic gloves whose thin form factor and high power density can hardly be achieved by conventional actuators.

Electrospun liquid crystal elastomer microfiber actuator

2021 ◽  
Vol 6 (57) ◽  
pp. eabi9704
Author(s):  
Qiguang He ◽  
Zhijian Wang ◽  
Yang Wang ◽  
Zijun Wang ◽  
Chenghai Li ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Power Density ◽  
High Power ◽  
Response Speed ◽  
Fast Response ◽  
Photothermal Effect ◽  
Isotropic Phase ◽  
High Power Density ◽  
Liquid Crystal Elastomer ◽  
Actuation Strain

Fibers capable of generating axial contraction are commonly seen in nature and engineering applications. Despite the broad applications of fiber actuators, it is still very challenging to fabricate fiber actuators with combined large actuation strain, fast response speed, and high power density. Here, we report the fabrication of a liquid crystal elastomer (LCE) microfiber actuators using a facile electrospinning technique. Owing to the extremely small size of the LCE microfibers, they can generate large actuation strain (~60 percent) with a fast response speed (<0.2 second) and a high power density (400 watts per kilogram), resulting from the nematic-isotropic phase transition of liquid crystal mesogens. Moreover, no performance degradation is detected in the LCE microfibers after 106 cycles of loading and unloading with the maximum strain of 20 percent at high temperature (90 degree Celsius). The small diameter of the LCE microfiber also results in a self-oscillatory behavior in a steady temperature field. In addition, with a polydopamine coating layer, the actuation of the electrospun LCE microfiber can be precisely and remotely controlled by a near-infrared laser through photothermal effect. Using the electrospun LCE microfiber actuator, we have successfully constructed a microtweezer, a microrobot, and a light-powered microfluidic pump.

Welding with high brilliance lasers and high power density

2010 ◽  
Author(s):  
Andreas Patschger ◽  
Markus Franz ◽  
Jens Bliedtner ◽  
Jean Pierre Bergmann
Keyword(s):  
Power Density ◽  
High Power ◽  
High Power Density

High power density of AlGaAs/InGaAs doped-channel FETs with low DC power supply

2001 ◽  
Vol 37 (9) ◽  
pp. 597
Author(s):  
H.C. Chiu ◽  
S.C. Yang ◽  
F.T. Chien ◽  
Y.J. Chan
Keyword(s):  
Power Density ◽  
High Power ◽  
Power Supply ◽  
High Power Density ◽  
Dc Power ◽  
Dc Power Supply

Investigation on Key Parameters of NI HTS Field Coils for High Power Density Synchronous Motors

2021 ◽  
Vol 31 (5) ◽  
pp. 1-5
Author(s):  
Uijong Bong ◽  
Chaemin Im ◽  
Jonghoon Yoon ◽  
Soobin An ◽  
Seok-Won Jung ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Power Density ◽  
Synchronous Motors

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

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