Effect of compliant layers within piezoelectric composites on power generation providing electrical stimulation in low frequency applications

Krech, Ember D.; Cadel, Eileen S.; Barrett, Ron; Friis, Elizabeth A.

doi:10.1016/j.jmbbm.2018.08.027

Cited by 9 publications

(26 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The final configuration was a seven-disc insert—seven discs connected electrically in parallel and stacked mechanically in series. The method for stacking discs was adapted from Krech et al [32]. All discs were connected electrically in parallel using two strips of copper foil 0.02 mm in thickness (Basic Copper, Carbondale, IL, USA) and silver conductive epoxy (EPO-TEK H20E, Epoxy Technology, Billerica, MA, USA), then cured for 2 h at 100 °C.…”

Section: Methodsmentioning

confidence: 99%

“…Layers of thin PZT discs, which are connected electrically in parallel and stacked mechanically in series, have been shown to produce 1–2 mW power at human walking loads and frequencies [28,29,30,31]. Recently, incorporating PZT discs in a composite for low-frequency power generation has been investigated, and the addition of a compliant layer between PZT discs, a CLACS (Compliant Layer Adaptive Composite Stack) structure, was shown to significantly increase power generation [32]. However, PZT disc composites have never been used as a generator for internal electronegative stimulation with the goal of increasing bone formation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stacked PZT Discs Generate Necessary Power for Bone Healing through Electrical Stimulation in a Composite Spinal Fusion Implant

et al. 2018

View full text Add to dashboard Cite

Electrical stimulation devices can be used as adjunct therapy to lumbar spinal fusion to promote bone healing, but their adoption has been hindered by the large battery packs necessary to provide power. Piezoelectric composite materials within a spinal interbody cage to produce power in response to physiological lumbar loads have recently been investigated. A piezoelectric macro-fiber composite spinal interbody generated sufficient power to stimulate bone growth in a pilot ovine study, despite fabrication challenges. The objective of the present study was to electromechanically evaluate three new piezoelectric disc composites, 15-disc insert, seven-disc insert, and seven-disc Compliant Layer Adaptive Composite Stack (CLACS) insert, within a spinal interbody, and validate their use for electrical stimulation and promoting bone growth. All implants were electromechanically assessed under cyclic loads of 1000 N at 2 Hz, representing physiological lumbar loading. All three configurations produced at least as much power as the piezoelectric macro-fiber composites, validating the use of piezoelectric discs for this application. Future work is needed to characterize the electromechanical performance of commercially manufactured piezoelectric stacks under physiological lumbar loads, and mechanically assess the composite implants according to FDA guidelines for lumbar interbody fusion devices.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stacked PZT Discs Generate Necessary Power for Bone Healing through Electrical Stimulation in a Composite Spinal Fusion Implant

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Piezoelectric CLACS in 3-3 mode from Krech et al were used in this study (Krech et al, 2018). Briefly, five through-thickness poled 10 × 0.4 mm discs of modified PZT-4 (SMD7T04R111, STEMiNC) were used to make three stack configurations of CLACS (n = 5 for each group) with 0 mm, 0.4 mm, and 0.8 mm compliant layer thicknesses of matrix epoxy (EPO-TEK 301, Epoxy Technology, Billerica, MA) interdigitated between the discs.…”

Section: Experimental Methods-clacs Fabricationmentioning

confidence: 99%

“…More recently, Krech, Cadel, Barrett, and Friis (2018) developed a new piezoelectric structural configuration, CLACS (compliant layer adaptive composite stacks), that included a layer of compliant material between each PZT element. This new structural configuration eliminated the previously mentioned fabrication challenges while still providing added toughness as a composite material.…”

mentioning

confidence: 99%

Analysis of how compliant layers and encapsulation affect power generated from piezoelectric stacked composites for bone healing medical devices

Cadel

Frazer

Krech

et al. 2019

J Biomedical Materials Res

View full text Add to dashboard Cite

Use of piezoelectric materials to harvest energy from human motion is commonly investigated. Traditional piezoelectric materials are inefficient at low frequencies but composite structures can increase efficiency at these frequencies. Compliant layer adaptive composite stack (CLACS) is a new piezoelectric PZT (lead zirconate titanate) structure designed for orthopedic implants to use loads generated during walking to provide electrical stimulation for bone healing. The CLACS structure increases power efficiency and structural properties as compared to PZT alone. The purpose of this study was to investigate the effects of compliant layer and encapsulation thicknesses on strain‐related parameters for CLACS predicted by finite element models. Percent changes in strain as compliant layer thickness increased were compared to percent changes in power experimentally produced by CLACS given similar geometries and loading conditions. Percent changes in PZT z‐strain matched the trends for increases in experimental power, but was not directly proportional. PZT z‐strain and radial strain increased as compliant layer and top and bottom encapsulation thickness increased. PZT z‐strain and radial strain decreased as side encapsulation thickness increased for a normalized distributed force on the PZT. The overall goal of this study was to inform future design decisions regarding CLACS structures specifically for use in orthopedic implants.

show abstract

“…Kumar et al [2] focused on the flexible hybrid piezoelectric-thermoelectric generator for harnessing electrical energy from mechanical and thermal energy, and the research is to integrate thermoelectric and piezoelectric in a small flexible device to harvest electrical energy from both thermal and mechanical energies. Krech et al [3] investigated the effect of compliant layers between piezoelectric discs and made conclusions for the effect of compliant layers within piezoelectric composites on power generation providing electrical stimulation in lowfrequency applications. In the study, piezoelectric energy generators based on spring and inertial mass, inertial massbased piezoelectric energy generators with and without a spring were designed and tested [4].…”

Section: Introductionmentioning

confidence: 99%

Electromechanical Model of Coupling Spring Piezoelectric Oscillator with Loading

Chen

Song

2020

Mathematical Problems in Engineering

View full text Add to dashboard Cite

The paper studies the influence of piezoelectric materials and structural parameters on the electromechanical conversion characteristics of the piezoelectric vibrator. Employing the mechanical theory of Euler–Bernoulli beam, the mechanical vibration and circuit balance equation are obtained about the single-step variable cross-section bimorph piezoelectric vibrator under the condition of external resistance, and the analytical equations are derived for the displacement, output voltage, and conversion efficiency of the piezoelectric vibrator excited by near natural frequency simple harmonic support. The validity of the theoretical model is verified by vibration test. Theoretical analysis and experimental results show that the mechanical and electrical conversion efficiency of the piezoelectric vibrator is the highest when the circuit impedance is matched, and the mechanical and electrical conversion efficiency of the piezoelectric vibrator is determined by the resistance ratio caused by mechanical and electrical coupling after resistance optimization.

show abstract

Effect of compliant layers within piezoelectric composites on power generation providing electrical stimulation in low frequency applications

Cited by 9 publications

References 31 publications

Stacked PZT Discs Generate Necessary Power for Bone Healing through Electrical Stimulation in a Composite Spinal Fusion Implant

Stacked PZT Discs Generate Necessary Power for Bone Healing through Electrical Stimulation in a Composite Spinal Fusion Implant

Analysis of how compliant layers and encapsulation affect power generated from piezoelectric stacked composites for bone healing medical devices

Electromechanical Model of Coupling Spring Piezoelectric Oscillator with Loading

Contact Info

Product

Resources

About