Mengbing Liang

Kirigami-based stretchable lithium- ion batteries

We have produced stretchable lithium-ion batteries (LIBs) using the concept of kirigami, i.e., a combination of folding and cutting. The designated kirigami patterns have been discovered and implemented to achieve great stretchability (over 150%) to LIBs that are produced by standardized battery manufacturing. It is shown that fracture due to cutting and folding is suppressed by plastic rolling, which provides kirigami LIBs excellent electrochemical and mechanical characteristics. The kirigami LIBs have demonstrated the capability to be integrated and power a smart watch, which may disruptively impact the field of wearable electronics by offering extra physical and functionality design spaces.

Origami-enabled deformable silicon solar cells

Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

Microscale Silicon Origami.

A new methodology to create 3D origami patterns out of Si nanomembranes using pre-stretched and pre-patterned polydimethylsiloxane substrates is reported. It is shown this approach is able to mimic paper-based origami patterns. The combination of origami-based microscale 3D architectures and stretchable devices will lead to a breakthrough on reconfigurable systems.

Three-Dimensional Flexible Thermal Sensor for Intravascular Flow Monitoring

A novel design and assembly technology is developed for a three-dimensional (3-D) flexible thermal flow sensor based on convective heat transfer to reduce detection error caused by position variation of a sensor inside the flow of narrow and curved geometries, such as coronary artery. The 3-D sensor has three independent sensing elements equally distributed around the catheter tube. This arrangement introduces three independent information channels, and cross-comparisons are used to provide accurate flow measurement. The resistance of the sensing elements is measured at ~ 1-1.2 kΩ with the temperature coefficient of resistance at 0.086%/°C. Using a constant-current circuit, the three sensing elements are heated to ~ 10°C above ambient temperature. Flow testing is implemented in a pipe channel at two positions: on the wall and along the center line. Experimental results from these two positions are discussed and computational fluid dynamic simulation based on Newtonian fluid properties is implemented, showing comparable results within an acceptable range of experimental to simulation errors. Therefore, we demonstrate the capability of 3-D thermal flow sensor for detecting the position of the catheter in the flow channel, thereby providing an accurate flow measurement.

Molecular Electronic Transducer-Based Low-Frequency Accelerometer Fabricated With Post-CMOS Compatible Process Using Droplet as Sensing Body

This letter reports a low-frequency micro-accelerometer implementing a liquid-state sensing body, based on molecular electronic transducer (MET) in post-CMOS compatible microfabrication technology. The device employs a sub-microliter electrolyte droplet encapsulated in oil as the sensing body, and a MET electrode configuration as the sensing read-out mechanism. The promising and unique performance of the MET design allows the fabricated device to achieve 10.8 V/G(G=9.81 m/s2) sensitivity at 20 Hz with nearly flat response over the frequency range from 1 to 50 Hz, and a low noise floor of 75 μG/√(Hz) at 20 Hz.

Molecular electronic transducer based planetary seismometer with new fabrication process

This paper describes a novel design and implementation of a short period seismometer based on molecular electronic transducer (MET) for the purpose of planetary exploration. A silicon on insulator (SOI)-based micro-fabrication is employed to reduce the hydraulic impedance of microfluidic channels in a MET device, resulting in improved noise floor and sensitivity. The resolution reached 1.78×10-7 (m/s2)/√Hz at 1.2 Hz with the sensitivity of 2500V/(m/s2).

MEMS accelerometer based on Molecular Electronic Transducers using Ionic Liquid

This paper demonstrates a novel MEMS accelerometer based on Molecular Electronic Transducers (MET) using Ionic Liquids (ILs) as sensing body to enable operation in a wide temperature range with better sensitivity. The Sensitivity has been improved for 8 times and the low operation temperature limit expands to at least -90 °C.