Morteza Amjadi

Assitant Professor

Alumni

Flexible electronics, wearable technology, and soft micro-/nanorobots.

MS: Korea Advanced Institute of Science and Technology (KAIST), South Korea, 2014
BS: Iran University of Science and Technology (IUST), Iran, 2012

Bioinspired microfibers for skin adhesion and signal amplification of wearable sensors

Considerable attention is being paid to wearable medical systems owing to their seamless integration with the human body, allowing continuous monitoring of important vital signs, such as respiratory and heart rate and greatly assists early diagnosis of diseases an...

Dirk Drotlef Morteza Amjadi

High-performance multiresponsive paper actuators

Soft actuator materials are being actively pursued owing to their importance in soft robotics, artificial muscles, biomimetic devices, and beyond. Electrically, chemically, and light-activated actuators are the mostly explored soft actuators. R...

Morteza Amjadi

Parallel microcracks-based ultrasensitive and highly stretchable strain sensors

Flexible electronic devices are a rising interest in both research and industry due to their facile interaction with the human body and surrounding environment. In particular, demand is dramatically increasing for flexible sensors due to their ...

Morteza Amjadi Mehmet Turan

Self-sensing paper actuators based on graphite-carbon nanotube hybrid films

In recent years, new emerging functional materials have considerably improved the deformation amplitude, response speed, force generation, and programmable motion output of soft actuators. Aside from efficient shape-changing behavior of so...

Morteza Amjadi

7 results (View BibTeX file of all listed publications)

2018

Self-Sensing Paper Actuators Based on Graphite–Carbon Nanotube Hybrid Films

Amjadi, M., Sitti, M.

Advanced Science, pages: 1800239, May 2018 (article)

Abstract

Abstract Soft actuators have demonstrated potential in a range of applications, including soft robotics, artificial muscles, and biomimetic devices. However, the majority of current soft actuators suffer from the lack of real-time sensory feedback, prohibiting their effective sensing and multitask function. Here, a promising strategy is reported to design bilayer electrothermal actuators capable of simultaneous actuation and sensation (i.e., self-sensing actuators), merely through two input electric terminals. Decoupled electrothermal stimulation and strain sensation is achieved by the optimal combination of graphite microparticles and carbon nanotubes (CNTs) in the form of hybrid films. By finely tuning the charge transport properties of hybrid films, the signal-to-noise ratio (SNR) of self-sensing actuators is remarkably enhanced to over 66. As a result, self-sensing actuators can actively track their displacement and distinguish the touch of soft and hard objects.

link (url) DOI Project Page [BibTex]

2018

Amjadi, M., Sitti, M. Self-Sensing Paper Actuators Based on Graphite–Carbon Nanotube Hybrid Films Advanced Science, pages: 1800239, May 2018 (article)

link (url) DOI Project Page [BibTex]

Recent Advances in Wearable Transdermal Delivery Systems

Amjadi, M., Sheykhansari, S., Nelson, B. J., Sitti, M.

Advanced Materials, 30(7):1704530, January 2018 (article)

Abstract

Abstract Wearable transdermal delivery systems have recently received tremendous attention due to their noninvasive, convenient, and prolonged administration of pharmacological agents. Here, the material prospects, fabrication processes, and drug‐release mechanisms of these types of therapeutic delivery systems are critically reviewed. The latest progress in the development of multifunctional wearable devices capable of closed‐loop sensation and drug delivery is also discussed. This survey reveals that wearable transdermal delivery has already made an impact in diverse healthcare applications, while several grand challenges remain.

link (url) DOI [BibTex]

Amjadi, M., Sheykhansari, S., Nelson, B. J., Sitti, M. Recent Advances in Wearable Transdermal Delivery Systems Advanced Materials, 30(7):1704530, January 2018 (article)

link (url) DOI [BibTex]

2017

Bioinspired Composite Microfibers for Skin Adhesion and Signal Amplification of Wearable Sensors

Drotlef, D., Amjadi, M., Yunusa, M., Sitti, M.

Advanced Materials, 29(28):1701353, May 2017, Back Cover (article)

Abstract

A facile approach is proposed for superior conformation and adhesion of wearable sensors to dry and wet skin. Bioinspired skin-adhesive films are composed of elastomeric microfibers decorated with conformal and mushroom-shaped vinylsiloxane tips. Strong skin adhesion is achieved by crosslinking the viscous vinylsiloxane tips directly on the skin surface. Furthermore, composite microfibrillar adhesive films possess a high adhesion strength of 18 kPa due to the excellent shape adaptation of the vinylsiloxane tips to the multiscale roughness of the skin. As a utility of the skin-adhesive films in wearable-device applications, they are integrated with wearable strain sensors for respiratory and heart-rate monitoring. The signal-to-noise ratio of the strain sensor is significantly improved to 59.7 because of the considerable signal amplification of microfibrillar skin-adhesive films.

DOI [BibTex]

2017

Drotlef, D., Amjadi, M., Yunusa, M., Sitti, M. Bioinspired Composite Microfibers for Skin Adhesion and Signal Amplification of Wearable Sensors Advanced Materials, 29(28):1701353, May 2017, Back Cover (article)

DOI [BibTex]

Recent Advances in Skin Penetration Enhancers for Transdermal Gene and Drug Delivery

Amjadia, M., Mostaghacia, B., Sittia, M.

Current Gene Therapy, 17, 2017 (article)

Abstract

There is a growing interest in transdermal delivery systems because of their noninvasive, targeted, and on-demand delivery of gene and drugs. However, efficient penetration of therapeutic compounds into the skin is still challenging largely due to the impermeability of the outermost layer of the skin, known as stratum corneum. Recently, there have been major research activities to enhance the skin penetration depth of pharmacological agents. This article reviews recent advances in the development of various strategies for skin penetration enhancement. We show that approaches such as ultrasound waves, laser, and microneedle patches have successfully been employed to physically disrupt the stratum corneum structure for enhanced transdermal delivery. Rather than physical approaches, several non-physical route have also been utilized for efficient transdermal delivery across the skin barrier. Finally, we discuss some clinical applications of transdermal delivery systems for gene and drug delivery. This paper shows that transdermal delivery devices can potentially function for diverse healthcare and medical applications while further investigations are still necessary for more efficient skin penetration of gene and drugs.

DOI [BibTex]

Amjadia, M., Mostaghacia, B., Sittia, M. Recent Advances in Skin Penetration Enhancers for Transdermal Gene and Drug Delivery Current Gene Therapy, 17, 2017 (article)

DOI [BibTex]

2016

High-Performance Multiresponsive Paper Actuators

Amjadi, M., Sitti, M.

ACS Nano, 10(11):10202-10210, American Chemical Society, October 2016 (article)

Abstract

There is an increasing demand for soft actuators because of their importance in soft robotics, artificial muscles, biomimetic devices, and beyond. However, the development of soft actuators capable of low-voltage operation, powerful actuation, and programmable shape-changing is still challenging. In this work, we propose programmable bilayer actuators that operate based on the large hygroscopic contraction of the copy paper and simultaneously large thermal expansion of the polypropylene film upon increasing the temperature. The electrothermally activated bending actuators can function with low voltages (≤ 8 V), low input electric power per area (P ≤ 0.14 W cm–2), and low temperature changes (≤ 35 °C). They exhibit reversible shape-changing behavior with curvature radii up to 1.07 cm–1 and bending angle of 360°, accompanied by powerful actuation. Besides the electrical activation, they can be powered by humidity or light irradiation. We finally demonstrate the use of our paper actuators as a soft gripper robot and a lightweight paper wing for aerial robotics.

DOI Project Page Project Page [BibTex]

2016

Amjadi, M., Sitti, M. High-Performance Multiresponsive Paper Actuators ACS Nano, 10(11):10202-10210, American Chemical Society, October 2016 (article)

DOI Project Page Project Page [BibTex]

Parallel microcracks-based ultrasensitive and highly stretchable strain sensors

Amjadi, M., Turan, M., Clementson, C. P., Sitti, M.

ACS Applied Materials \& Interfaces, 8(8):5618-5626, American Chemical Society, Febuary 2016 (article)

Abstract

There is an increasing demand for flexible, skin-attachable, and wearable strain sensors due to their various potential applications. However, achieving strain sensors with both high sensitivity and high stretchability is still a grand challenge. Here, we propose highly sensitive and stretchable strain sensors based on the reversible microcrack formation in composite thin films. Controllable parallel microcracks are generated in graphite thin films coated on elastomer films. Sensors made of graphite thin films with short microcracks possess high gauge factors (maximum value of 522.6) and stretchability (ε ≥ 50%), whereas sensors with long microcracks show ultrahigh sensitivity (maximum value of 11 344) with limited stretchability (ε ≤ 50%). We demonstrate the high performance strain sensing of our sensors in both small and large strain sensing applications such as human physiological activity recognition, human body large motion capturing, vibration detection, pressure sensing, and soft robotics.

DOI [BibTex]

Amjadi, M., Turan, M., Clementson, C. P., Sitti, M. Parallel microcracks-based ultrasensitive and highly stretchable strain sensors ACS Applied Materials \& Interfaces, 8(8):5618-5626, American Chemical Society, Febuary 2016 (article)

DOI [BibTex]

Stretchable, Skin-Mountable, and Wearable Strain Sensors and Their Potential Applications: A Review

Amjadi, M., Kyung, K., Park, I., Sitti, M.

Advanced Functional Materials, 26, pages: 1678-1698, Febuary 2016 (article)

Abstract

There is a growing demand for flexible and soft electronic devices. In particular, stretchable, skin-mountable, and wearable strain sensors are needed for several potential applications including personalized health-monitoring, human motion detection, human-machine interfaces, soft robotics, and so forth. This Feature Article presents recent advancements in the development of flexible and stretchable strain sensors. The article shows that highly stretchable strain sensors are successfully being developed by new mechanisms such as disconnection between overlapped nanomaterials, crack propagation in thin films, and tunneling effect, different from traditional strain sensing mechanisms. Strain sensing performances of recently reported strain sensors are comprehensively studied and discussed, showing that appropriate choice of composite structures as well as suitable interaction between functional nanomaterials and polymers are essential for the high performance strain sensing. Next, simulation results of piezoresistivity of stretchable strain sensors by computational models are reported. Finally, potential applications of flexible strain sensors are described. This survey reveals that flexible, skin-mountable, and wearable strain sensors have potential in diverse applications while several grand challenges have to be still overcome.

DOI [BibTex]

Amjadi, M., Kyung, K., Park, I., Sitti, M. Stretchable, Skin-Mountable, and Wearable Strain Sensors and Their Potential Applications: A Review Advanced Functional Materials, 26, pages: 1678-1698, Febuary 2016 (article)

DOI [BibTex]

Morteza Amjadi

Bioinspired microfibers for skin adhesion and signal amplification of wearable sensors

High-performance multiresponsive paper actuators

Parallel microcracks-based ultrasensitive and highly stretchable strain sensors

Self-sensing paper actuators based on graphite-carbon nanotube hybrid films

2018

Self-Sensing Paper Actuators Based on Graphite–Carbon Nanotube Hybrid Films

2018

Recent Advances in Wearable Transdermal Delivery Systems

2017

Bioinspired Composite Microfibers for Skin Adhesion and Signal Amplification of Wearable Sensors

2017

Recent Advances in Skin Penetration Enhancers for Transdermal Gene and Drug Delivery

2016

High-Performance Multiresponsive Paper Actuators

2016

Parallel microcracks-based ultrasensitive and highly stretchable strain sensors

Stretchable, Skin-Mountable, and Wearable Strain Sensors and Their Potential Applications: A Review

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