Paper-Based Supercapacitive Mechanical Sensors

Abstract

Paper has been pursued as an interesting substrate material for sensors in applications such as microfluidics, bio-sensing of analytes and printed microelectronics. It offers advantages of being inexpensive, lightweight, environmentally friendly and easy to use. However, currently available paper-based mechanical sensors suffer from inadequate range and accuracy. Here, using the principle of supercapacitive sensing, we fabricate force sensors from paper with ultra-high sensitivity and unprecedented configurability. The high sensitivity comes from the sensitive dependence of a supercapacitor’s response on the contact area between a deformable electrolyte and a pair of electrodes. As a key component, we develop highly deformable electrolytes by coating ionic gel on paper substrates which can be cut and shaped into complex three-dimensional geometries. Paper dissolves in the ionic gel after determining the shape of the electrolytes, leaving behind transparent electrolytes with micro-structured fissures responsible for their high deformability. Exploiting this simple paper-based fabrication process, we construct diverse sensors of different configurations that can measure not just force but also its normal and shear components. The new sensors have range and sensitivity several orders of magnitude higher than traditional MEMS capacitive sensors, in spite of their being easily fabricated from paper with no cleanroom facilities.

Ionic Flexible Sensors: Mechanisms, Materials, Structures, and Applications

“…Other Polymer Matrices: Many materials used in daily lives, such as, paper, [127,128] and fabric [35,129] and so on, can also be used as the matrix of ionic sensors, owing to the similarity of their structure to macromolecular polymers or large amounts of ions. The plant material is a 3D cell wall network that acts like a compressible metamaterial, which elastically collapses upon pressing with some specific surface structures.…”

Ionogel-based flexible stress and strain sensors

“…Sandwiched electric skin and integrated with circuit; sensor array [69] Pressure Solution cast Sandwiched membrane with chamber and sensor array [71] Tactile and pressure Printing or writhing All-paper based sensor array [73] Pressure Paper-based and packaged with complex shaped shell [72] All-paper based, sandwiched with printing electrodes and has different origami structures [74] Electro-spinning All-fabrics based sensor sandwiched with conductive fabrics [67] Sandwiched with Al foil and insulator shell [76]…”

“…All-paper based IFSS has another major merit: various structure designs. They could be tailored into different kirigami structures or folded into fancy origami structures [72,73,74].…”

Microwave‐Assisted Rapid Synthesis of Urchin‐Like Bimetallic Mn–Co Carbonate Composites for High‐Performance Supercapacitors

“…[7] Electrochemical materials can be classified into electrical double-layer capacitors (EDLCs) and pseudo-capacitors according to the energy storage mechanism. [6][7][8][9][10] EDLCs store energy purely via accumulating charges on the electrode surface, [4] but pseudocapacitors utilize a rapid and reversible redox reaction on the surface of the electrode and have received greater attention. [11][12][13] It is well-known that choosing suitable electrode material is the key factor for the high performance of supercapacitors.…”