Paper-based piezoresistive MEMS sensors

Abstract

This paper describes the development of MEMS force sensors constructed using paper as the structural material. The working principle on which these paper-based sensors are based is the piezoresistive effect generated by conductive materials patterned on a paper substrate. The device is inexpensive (~$0.04/device for materials), simple to fabricate, light weight, and disposable. Paper can be readily folded into three-dimensional structures to increase the stiffness of the sensor while keeping it light in weight. The entire fabrication process can be completed within one hour without expensive cleanroom facilities using simple tools (e.g., a paper cutter and a painting knife). We demonstrated that the paper-based sensor can measure forces with moderate performance (i.e., resolution: 120 µN, measurement range: ±16 mN, and sensitivity: 0.84 mV/mN), and we applied this sensor to characterizing the mechanical properties of a soft material. Leveraging the same sensing concept, we also developed a paper-based balance with a measurement range of 15 g, and a resolution of 390 mg.2

Electrically Activated Paper Actuators

“…cost, weight, printability, and porosity), HEPAs could be useful in applications benefitting from monolithic integration in paper-based printed microfluidic [6][7][8][9][10] and electronic devices, [16][17][18][19][20][21][22] paper MEMS, [16,23,24] printable and foldable micro machines, [24][25][26] and robots. [25,27,40] Their speed of actuation, and the force they produce, however, is low (by standards of more conventional electromagnetic and pneumatic / hydrolic systems), but they are also lighter, much less expensive, and much more easily integrated with paper devices (diagnostic, bioanalytical, and electromechanical systems, for example) than are the more universal systems.…”

“…[3][4][5] For example, we and others have used it for microfluidic [6][7][8][9][10] and electroanalytical devices as the basis for low-cost diagnostics, [11,12] as 3-D scaffolds for cell growth, [13][14][15] as a substrate for printed electronics, [16][17][18][19][20][21][22] and in micro-electromechanical systems (MEMS). [16,23,24] A missing component for paper-based devices is an electrically controlled actuator that is embedded within the paper, can be fabricated by printing, and continues to operate when the paper that supports it is creased and/or folded. Paper actuators that fulfill these requirements have the potential to allow control of liquid transport in paperbased microfluidic devices, to enable assembly of micro machines through self-folding, [24][25][26] and to serve as microactuators for paper devices.…”

Elastomeric Origami: Programmable Paper‐Elastomer Composites as Pneumatic Actuators

“…iv) Fabrication of prototypes of soft actuators based on paper-elastomer composites requires only low-cost tooling and handwork. v) Paper can also be used as a substrate for laying out sensors [31] and electromechanical systems [32] that would improve the adaptive interaction between a soft robot or actuator and its environment or task.…”

A Hybrid Combining Hard and Soft Robots

“…For closed-loop feedback in the robotic system, we chose paperbased piezoresistive MEMS sensors 20,21 because they are inexpensive and easy to fabricate. The sensors allowed the control system to adapt the direction of locomotion of the robot to the presence of obstacles.…”

“…Feedback when gripping using soft machines is possible using compliant, low-cost, sensors such as those by Kramer,[12][13][14] Mazzeo, 20 and Liu et al 21 Systems that use a composite of extensible, and inextensible, materials have been shown to be capable of complex motion using simple control inputs. 14 and the bioinspired approaches using tissue engineering by Nowroth et al 15 and Feinberg et al 16 …”