Assembly and Disassembly of Bare Chips using On-Substrate Linear Microvibromotor Arrays

A new method for the on-substrate fine positioning of micro/meso-scale discrete components is proposed, where component positions are finely adjusted using micro linear sliders and fixtures on the substrate. Each micro linear slider is actuated by vibratory impacts exerted by two pairs of micro cantilever impacters. These micro cantilever impacters are selectively resonated by shaking the entire substrate with a piezoelectric vibrator realizing forward and backward slider motion to facilitate assembly and disassembly of a micro component on the substrate. An array of the prototype externally-resonated linear micro vibrometers is fabricated using the MCNC MUMPS service. These prototypes are tested for forward and backward motion via external vibration applied by a piezoelectric stack vibrator. The linear micro vibromotor array is to be integrated in a on-chip micro assembly device where the assembly of micro/meso-scale discrete components (bare chips) on a common substrate is done by the combination of vibratory palletization for gross positioning, and linear micro vibromotor for fine positioningPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87251/4/Saitou103.pd

Externally Resonated Linear Microvibromotor for Microassembly

A new method for on-substrate fine positioning of microscale/mesoscale discrete components is presented, where component positions are finely adjusted using microlinear sliders and fixtures on the substrate. Each microlinear slider is actuated by vibratory impacts exerted by two pairs of microcantilever impacters. These microcantilever impacters are selectively resonated by shaking the entire substrate with a piezoelectric vibrator, requiring no need for built-in driving mechanisms such as electrostatic comb actuators, as reported previously. This selective resonance of the microcantilever impacters via an external vibration energy field provides with a very simple means of controlling forward and backward motion of the microlinear slider, facilitating assembly and disassembly of a microcomponent on a substrate. An analytical model of the device is derived in order to obtain, through the simulated annealing algorithm, an optimal design, which maximizes translation speed of the linear slider at desired external input frequencies. Prototypes of the externally resonated linear microvibromotor are fabricated using the three-layer polysilicon surface micromachining process provided by the Microelectronics Center of North Carolina, Research Triangle Park, NC, multiuser microelectromechanical processes service. These prototypes are tested for forward and backward motion via external vibration applied by an piezoelectric flexure vibrator, as well as the horizontal positioning and release of 500-_m-square polysilicon chips against a reference fixture element anchored to the substratePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87262/4/Saitou41.pd

Variants in STXBP3 are Associated with Very Early Onset Inflammatory Bowel Disease, Bilateral Sensorineural Hearing Loss and Immune Dysregulation

Background and aims: Very early onset inflammatory bowel disease [VEOIBD] is characterized by intestinal inflammation affecting infants and children less than 6 years of age. To date, over 60 monogenic aetiologies of VEOIBD have been identified, many characterized by highly penetrant recessive or dominant variants in underlying immune and/or epithelial pathways. We sought to identify the genetic cause of VEOIBD in a subset of patients with a unique clinical presentation. Methods: Whole exome sequencing was performed on five families with ten patients who presented with a similar constellation of symptoms including medically refractory infantile-onset IBD, bilateral sensorineural hearing loss and, in the majority, recurrent infections. Genetic aetiologies of VEOIBD were assessed and Sanger sequencing was performed to confirm novel genetic findings. Western analysis on peripheral blood mononuclear cells and functional studies with epithelial cell lines were employed. Results: In each of the ten patients, we identified damaging heterozygous or biallelic variants in the Syntaxin-Binding Protein 3 gene [STXBP3], a protein known to regulate intracellular vesicular trafficking in the syntaxin-binding protein family of molecules, but not associated to date with either VEOIBD or sensorineural hearing loss. These mutations interfere with either intron splicing or protein stability and lead to reduced STXBP3 protein expression. Knock-down of STXBP3 in CaCo2 cells resulted in defects in cell polarity. Conclusion: Overall, we describe a novel genetic syndrome and identify a critical role for STXBP3 in VEOIBD, sensorineural hearing loss and immune dysregulation.info:eu-repo/semantics/publishedVersio

Externally-Resonated Micro Linear Vibromotor for Micro Assembly

A new design of a linear micro vibromotor for on-substrate fine positioning of micro-scale components is presented where a micro linear slider is actuated by vibratory impacts exerted by micro cantilever impacters. These micro cantilever impacters are selectively resonated by shaking the entire substrate with a piezoelectric vibrator, requiring no need for built-in driving mechanisms such as electrostatic comb actuators as reported previously. This selective resonance of the micro cantilever impacters via an external vibration energy field provides with a very simple means of controlling forward and backward motion of the micro linear slider, facilitating assembly and disassembly of a micro component on a substrate. The double-V beam suspension design is employed in the micro cantilever impacters for larger displacement in the lateral direction while achieving higher stiffness in the transversal direction. An analytical model of the device is derived in order to obtain, through the Simulated Annealing algorithm, an optimal design which maximizes translation speed of the linear slider at desired external input frequencies. Prototypes of the externally-resonated linear micro vibromotor are fabricated using the three-layer polysilicon surface micro machining process provided by the MCNC MUMPS service.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87279/4/Saitou104.pd

The predictive properties of frailty-rating scales in the acute medical unit.

BACKGROUND: older people are at an increased risk of adverse outcomes following attendance at acute hospitals. Screening tools may help identify those most at risk. The objective of this study was to compare the predictive properties of five frailty-rating scales. METHOD: this was a secondary analysis of a cohort study involving participants aged 70 years and above attending two acute medical units in the East Midlands, UK. Participants were classified at baseline as frail or non-frail using five different frailty-rating scales. The ability of each scale to predict outcomes at 90 days (mortality, readmissions, institutionalisation, functional decline and a composite adverse outcome) was assessed using area under a receiver-operating characteristic curve (AUC). RESULTS: six hundred and sixty-seven participants were studied. Frail participants according to all scales were associated with a significant increased risk of mortality [relative risk (RR) range 1.6-3.1], readmission (RR range 1.1-1.6), functional decline (RR range 1.2-2.1) and the composite adverse outcome (RR range 1.2-1.6). However, the predictive properties of the frailty-rating scales were poor, at best, for all outcomes assessed (AUC ranging from 0.44 to 0.69). CONCLUSION: frailty-rating scales alone are of limited use in risk stratifying older people being discharged from acute medical units